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Exercise

Episodes

Posted on April 22nd 2025 (28 days)

Dr. Andy Galpin & Dr. Rhonda Patrick discuss nutrition, supplement, and recovery strategies for improving exercise performance.

Posted on April 1st 2025 (about 2 months)

In this clip from the Rich Roll Podcast, Dr. Rhonda Patrick explains how exercise-driven brain changes support learning, memory, and mental health.

Posted on April 1st 2025 (about 2 months)

In this clip from the Rich Roll Podcast, Dr. Rhonda Patrick discusses how exercise compares to medication for diabetes, blood pressure, and depression.

Topic Pages

  • Aerobic exercise

    Aerobic exercise, physical activity that increases breathing and heart rate, promotes cardiovascular, brain, and whole-body health.

  • Age-related decline of muscle power (powerpenia)

    Muscle power is the ability to generate force quickly and is a biomarker of healthy aging.

  • Autophagy

    Autophagy, or “self-eating,” is a response to stress in which a cell destroys damaged or dysfunctional components in order to adapt to external conditions.

  • Berberine

    Berberine is a plant-based compound with pharmacological actions that share many features with metformin.

  • Beta-hydroxybutyrate

    Beta-hydroxybutyrate is a ketone body and source of cellular energy produced via the breakdown of fats during carbohydrate scarcity and fasting.

  • Brain-derived neurotrophic factor (BDNF)

    BDNF is a growth factor known for its influence on neuronal health and for its role in mediating the beneficial cognitive effects associated with exercise.

  • Butyrate

    Butyrate is a short-chain fatty acid produced by microbes in the gut during the fermentation of dietary fiber.

  • Depression

    Depression – a neuropsychiatric disorder affecting 322 million people worldwide – is characterized by negative mood and metabolic, hormonal, and immune disturbances.

  • Exercise and Cognitive Function

    Physical activity boosts brain blood flow and stimulates the production of neurochemicals, creating a flurry of neural activity and improved cognitive function.

  • Exercise and Weight Loss

    Exercise is promoted widely as a strategy for weight loss as it increases total daily energy expenditure and creates an energy deficit.

  • Exercise Intensity

    Vigorous exercise exerts several benefits on cardiovascular health, metabolic health, and longevity.

  • Metformin

    Metformin, a drug commonly used to treat type 2 diabetes, may modulate certain aging processes.

  • Nicotinamide mononucleotide

    Nicotinamide mononucleotide is a precursor of NAD+, a coenzyme necessary for cellular energy production and DNA repair. It is available as a supplement.

  • Resveratrol

    Resveratrol is a polyphenolic compound produced in plants that demonstrates anti-inflammatory and anti-aging properties in humans.

  • Sauna

    Sauna use exposes the body to extreme heat and, in turn, induces protective responses that improve health and may increase healthspan.

  • Vitamin C

    Vitamin C is an essential nutrient, widely recognized for its antioxidant properties and its roles in many critical processes and pathways.

News & Publications

  • Vitamin D, a fat-soluble nutrient, is sequestered in adipose tissue, limiting its circulation—an effect amplified in obesity. Obese adults, for example, exhibit a 57 % smaller rise in circulating vitamin D₃ after whole-body ultraviolet exposure and are more than half as likely to reach sufficient vitamin D levels than normal-weight adults. Against this backdrop, the VitaDEx randomized trial showed that ten weeks of indoor exercise during winter sharply attenuated seasonal vitamin D loss and fully preserved its active hormone, 1,25(OH)₂D₃—without weight loss or supplementation.

    • Active hormone maintained: Exercise fully prevented the winter decline in 1,25(OH)₂D₃, while controls experienced a 15 % drop. (The precursor 25-hydroxy-vitamin D fell only 15 % in exercisers versus 25 % in sedentary controls.)
    • Adipose sequestration puzzle: Contrary to expectations, adipose vitamin D concentrations remained largely unchanged. “Exercise did not drive a greater decrease in adipose tissue concentrations of vitamin D…there was no correlation between the change in serum 25(OH)D and changes in adipose vitamin D₃ concentrations.”
    • Mechanistic pivot: Researchers suggested possible transient vitamin D mobilization, depot-specific effects, or direct metabolic adaptations improving vitamin D efficiency. They speculated that regular physical activity might enable “more ‘efficient’ vitamin D metabolism, making better use of the available substrate to generate the active metabolite without tipping the balance into a negative feedback loop.”

    Taken together, the findings indicate exercise is not merely releasing vitamin D from fat stores; it is altering the flux and enzymatic handling of the hormone, offering a route to restore endocrine availability where supplementation often fails in obesity.

    Press Release: Regular Exercise Helps Maintain Vitamin D Levels During Winter
    Study: Exercise without Weight Loss Prevents Seasonal Decline in Vitamin D Metabolites: The VitaDEx Randomized Controlled Trial

  • Training in hot conditions can drive marked improvements in endurance by triggering cardiovascular and thermoregulatory adaptations. However, access to heat training chambers is limited, and the physical demands of exercising in high temperatures can be risky or impractical. A recent study found that sitting in a sauna or soaking in hot water after exercise—a practice known as “passive heat acclimation"—might offer some of the same benefits as working out in the heat, but the evidence was weak and inconsistent.

    Researchers reviewed 10 studies involving nearly 200 healthy adults, comparing those who used post-exercise heat exposure via sauna or hot water immersion to those who did not. All participants completed similar exercise training programs, and the researchers analyzed outcomes related to performance in hot or neutral conditions, aerobic capacity, heart rate, body temperature, sweat response, and perceived exertion.

    The analysis revealed little to no improvement in performance for those using passive heat acclimation, identifying only a 4% difference between groups—an effect that was statistically weak and inconsistent across individuals. Heat exposure slightly improved maximum oxygen uptake, sweat rate, and thermal discomfort ratings. However, the overall certainty of the evidence was low to very low, due to small study sizes and inconsistent reporting.

    These findings suggest that while passive heat exposure may exert some physiological effects, its ability to improve exercise performance remains unclear. More rigorous, well-controlled trials are needed before recommending hot tubs or saunas as a reliable substitute for training in the heat. Learn more about heat exposure in this peer-reviewed article by Dr. Rhonda Patrick.

  • Resistance training is a powerful tool for improving the health and well-being of older adults, but many guidelines focus on higher training volumes that may be difficult for some to achieve or maintain. A recent study found that once-weekly, low-volume resistance training boosted physical functioning, energy, and social engagement in older adults, reducing pain by up to 40% and improving strength by 30%.

    Researchers assigned 31 older adults (average age, 66) to one of four groups. Participants trained once a week for six weeks, doing leg press exercises with either a slower, controlled pace or a more explosive effort and using lighter or heavier weekly exercise “doses” (either three or five sets of five repetitions). The researchers assessed the participants' quality of life, functional capacity, strength, and body mass at baseline and weeks 3 and 6.

    They found that participants moved more easily, felt more energetic, and reported less pain after the intervention. Their balance and strength improved, and many participants reported more frequent physical activity—an average increase of 25%—and a 20% improvement in mental health. Most participants (85%) continued exercising after the study, and 95% said they would recommend the program. Many valued the structure and support, with 75% finding the shorter three-by-five routine practical and sustainable.

    These findings suggest that lower-dose, once-weekly resistance training interventions can produce meaningful health improvements in older adults. One of the principal benefits of resistance training is building muscle, which is critical for maintaining health during aging. Learn how it’s never too late to start building muscle in this clip featuring Dr. Rhonda Patrick.

  • As people age, sleeping problems become more common, often affecting mood, memory, and overall health. A recent study found that resistance training improves sleep in older adults better than other forms of exercise.

    Researchers analyzed 25 clinical trials involving more than 2,100 people to see how different kinds of physical activity influenced sleep quality. They looked specifically at the Pittsburgh Sleep Quality Index, a subjective measure of a person’s sleep quality. The studies compared people who exercised to those who adhered to their usual routines, received health education, or did no physical activity at all.

    Strength training was the most effective approach for improving sleep scores, followed by aerobic activity and then a combination of both. People who engaged in strength exercises were more likely to report better sleep, with the strongest improvement observed across all comparisons. Aerobic activity also helped but wasn’t as effective, and combined exercise had a more modest benefit.

    These findings suggest that resistance training does more than build muscle—it also improves sleep. Resistance training builds bone, too, a critical component of aging well. Learn more in this clip featuring Dr. Brad Schoenfeld.

  • Taking an omega-3 supplement may do more than support heart health—it might enhance the effects of your workout. A recent study found that combining omega-3 supplementation with exercise training improved body composition and cardiometabolic health better than exercise alone.

    Researchers conducted a systematic review and meta-analysis of 21 studies comparing exercise training combined with omega-3 supplementation to exercise training alone. The studies involved 673 adults aged 30 to 70, with an average body mass index (BMI) of 24 to 37. The analysis focused on outcomes such as body fat, blood pressure, blood fats, blood sugar, inflammation, and muscle mass, while accounting for variations across the studies.

    They found that adding omega-3 supplements to an exercise routine resulted in modest improvements. Participants lost just over 1 kilogram (2.3 pounds) more body fat and lowered their triglyceride levels by 10% compared to those who exercised without supplements. They also experienced drops in blood pressure—around 4 mmHg lower for both systolic and diastolic pressures—and slightly reduced levels of tumor necrosis factor-alpha, a marker of inflammation. However, LDL cholesterol increased slightly. Notably, participants also improved their lower-body strength but observed no additional benefits in other areas such as BMI, lean body mass, or blood glucose control.

    These findings indicate that omega-3 supplements enhance certain health benefits of exercise, particularly in decreasing fat mass, lowering blood pressure, and boosting muscle strength. Although the changes were modest, they could accumulate over time, especially for adults aiming to improve their cardiometabolic health. Some evidence suggests that omega-3s exert anabolic effects, too. Learn more in this episode featuring Dr. Chris McGlory.

  • Even if you work out, spending most of your day sitting may still adversely affect your health in ways that don’t become apparent until later in life. A recent study found that 35-year-olds who engaged in 30 minutes of vigorous exercise each day had cholesterol levels comparable to those of sedentary 30-year-olds, suggesting that vigorous exercise can offset up to five years of age-related decline in heart health.

    Researchers analyzed data from adults aged 28 to 49 who participated in the Colorado Adoption/Twin Study of Lifespan Behavioral Development and Cognitive Aging. They tracked the time participants spent sitting each day and how often they engaged in moderate or vigorous physical activity. To isolate the effects of behavior from shared genetics and environment, the researchers also compared identical twins with differing activity and sitting patterns. They examined two key health markers: body mass index and the ratio of total to high-density lipoprotein cholesterol—a strong predictor of heart disease risk.

    They found that people who spent more time sitting tended to have higher body mass index and worse cholesterol ratios as they aged. However, among those who sat for the same amount of time—about four hours daily—participants who exercised vigorously for at least 30 minutes daily had cholesterol profiles that resembled those of people five years younger. In some cases, vigorous activity was associated with health markers typical of people up to 10 years younger, but the protective effect weakened with longer sitting durations. In other words, exercise helped—but only to a point.

    These findings suggest that while vigorous exercise offers clear benefits, reducing sitting time is just as important for maintaining good health. “Exercise snacks” can offset the harmful effects of prolonged sitting. Learn more in this clip featuring Dr. Rhonda Patrick and Brady Holmer.

  • Creatine monohydrate—one of the most widely studied and popular supplements—has a well-earned reputation for helping increase lean body mass, but some of those gains may come from changes in body water rather than actual muscle growth. A recent study found that creatine monohydrate alone, even without exercise, can boost lean body mass in the short term—especially in women.

    Researchers randomly assigned 63 healthy adults to take either 5 grams of creatine monohydrate daily or nothing. After a one-week “wash-in” period with the supplement, everyone began a 12-week resistance training program. The researchers measured lean body mass using a body scan before and after the wash-in and after the training program.

    After one week of taking creatine without exercising, those who used the supplement had gained about 0.5 kilograms (roughly 1.1 pounds) more lean body mass than the control group—a difference most apparent in women. Once training began, both groups gained about 2 kilograms (4.4 pounds) of lean body mass over 12 weeks, but creatine users did not gain more than those who did not take it, indicating the supplement gave an early bump in lean body mass but did not enhance long-term gains from resistance training.

    These findings suggest that short-term creatine use can raise lean body mass measurements, likely by increasing body water. The investigators posited that higher doses or different timing strategies may be necessary to see continued benefits beyond that initial increase. Learn more about creatine in this episode featuring Dr. Darren Candow.

  • Heart disease is the leading cause of death worldwide, and clogged arteries—caused by a buildup of fatty plaques—are a major culprit. While some plaques remain stable, others can rupture and trigger heart attacks. A recent study found that high-intensity interval training (HIIT) may help shrink fatty arterial plaquesin people with coronary artery disease who have undergone stent placement, reducing plaque size by 1.2% in just six months.

    Researchers randomly assigned 60 patients with stable coronary artery disease to a supervised HIIT program or standard preventive care twice a week. After six months, they used intravascular ultrasound to measure changes in plaque size inside the coronary arteries.

    They found that patients who did HIIT had a 1.2% reduction in plaque size, while those who followed standard preventive care saw no change. The total plaque volume in the HIIT group also dropped by about 9 cubic millimeters, but it remained the same in the standard care group. Even small reductions in plaque size can be meaningful because they reflect a slowing—or even a reversal—of coronary artery disease progression.

    These findings suggest that HIIT may help slow or even reverse the progression of coronary artery disease. It’s important to note that these patients were closely supervised to minimize risk. Learn about some of the contraindications and considerations for HIIT in this episode featuring Dr. Martin Gibala.

  • If you’re struggling to remember things, a robust workout might help. Scientists have discovered that exercise can increase levels of brain-derived neurotrophic factor (BDNF), a protein that supports learning and memory. A recent study in rats found that low-speed uphill exercise raises blood lactate levels, increasing lactate and BDNF in key brain regions involved in cognition.

    Researchers divided rats into three groups: One remained inactive, another walked on a flat treadmill, and a third walked uphill at a 40% incline. The exercise sessions lasted either 30 or 90 minutes. To see if lactate from the blood contributed to brain changes, some rats also received a direct lactate injection.

    Uphill exercise increased lactate levels in the animals' blood and brains, while flat treadmill walking did not. After 90 minutes, uphill exercise also raised BDNF levels in brain regions linked to memory and learning. The lactate injection showed that blood lactate passed into the brain, reinforcing that exercise-induced increases in blood lactate can influence brain chemistry.

    These findings suggest that walking uphill—even slowly—provides cognitive benefits by raising brain lactate and stimulating BDNF production. This type of exercise could be a practical and safe way to support brain health, especially for older adults or those looking to enhance memory and learning. To learn more strategies to boost brain health, check out the Cognitive Enhancement Blueprint, a member-only perk.

  • Tendons are essential for force transmission between muscles and bones. However, as people age, tendons lose collagen and stiffen, impairing athletic performance and increasing injury risk. A recent study found that combining resistance exercise with collagen supplementation enhanced tendon health in middle-aged men.

    Researchers investigated the effects of 12 weeks of resistance exercise and collagen supplementation on patellar tendon properties in 20 middle-aged men. Both groups engaged in progressive lower-body resistance training twice weekly and received either 30 grams of hydrolyzed collagen or a placebo after training. The researchers evaluated the participants' tendon size, stiffness, and strength before and after the intervention.

    They found that participants who took collagen experienced a greater increase in patellar tendon cross-sectional area (+6.8 mm²) than the placebo group (+1.2 mm²). They also experienced a twofold greater increase in tendon stiffness and measures of tendon strength than the placebo group. Both groups experienced muscle strength and explosive power improvements, but tendon adaptations were more pronounced with collagen supplementation.

    These findings suggest that 12 weeks of resistance training with collagen supplementation enhances patellar tendon properties in middle-aged men. The patellar tendon is a strong, fibrous connective tissue that connects the bottom of the kneecap (patella) to the top of the shinbone (tibia). It plays a crucial role in movements like walking, running, jumping, and squatting, as it helps control the movement and stability of the knee joint. Learn more about the benefits of collagen supplementation in our overview article.

  • Infrared saunas are gaining in popularity among athletes as a recovery tool, but their effects on strength training adaptations remain uncertain. While traditional saunas can impair performance, infrared saunas may offer a more effective and comfortable recovery option. A recent study found that using infrared saunas after exercise enhances power production but doesn’t influence muscle growth.

    Forty female team sport athletes participated in the study, with half using an infrared sauna after training sessions for six weeks. Sauna sessions were done three times weekly for 10 minutes at 50°C (122°F) following their training. All participants underwent body composition measurements and physical performance tests, including sprint tests, jumps, and leg press exercises, before and after the training period.

    Both groups improved in neuromuscular performance and muscle size. However, the infrared sauna group showed greater jump height and peak power improvements, with a 25% increase in jump height and a 6.8% increase in peak power. Five-minute sprint times were also faster in the infrared sauna group, though not statistically significant. While both groups gained lean mass, the infrared sauna group experienced small body mass and fat mass increases. There were no marked differences between the groups in muscle hypertrophy or other body composition changes.

    These findings suggest that post-exercise infrared sauna use enhances power output over time but doesn’t affect muscle growth. Learn more about the benefits of infrared and traditional sauna use in our overview article.

  • Cancer remains one of the leading causes of death globally, with millions of new cases and deaths each year. Despite treatment advancements, cancer patients are at a greater risk of death due to muscle loss, heart complications, and inadequate physical activity. A recent study found that higher muscle strength and cardiorespiratory fitness reduce the risk of death in cancer patients, with a 31% to 46% lower likelihood of premature death.

    Researchers conducted a systematic review and meta-analysis of 42 studies involving more than 47,000 cancer patients across various types and stages to examine how muscle strength and cardiorespiratory fitness influence survival rates. They sought to determine whether higher fitness levels were associated with better outcomes in terms of overall and cancer-specific death.

    Their analysis revealed that patients with higher muscle strength or cardiorespiratory fitness were 31% to 46% less likely to die prematurely from any cause than those with lower fitness levels. Each increase in muscle strength was associated with an 11% lower risk of all-cause mortality. Furthermore, patients with advanced cancer stages, as well as those with lung and digestive cancers, saw significant reductions in death risks—ranging from 8% to 46% lower for all-cause mortality. Increments in cardiorespiratory fitness were particularly important, with each improvement in cardiorespiratory fitness linked to an 18% reduced risk of dying specifically from cancer.

    These findings suggest that boosting muscle strength and cardiorespiratory fitness can improve cancer patients' survival rates. Given the strong connection between physical fitness and mortality risk, health professionals should prioritize fitness assessments for cancer patients as part of their treatment strategies. Learn more about the role of exercise in cancer prevention and recurrence in this episode featuring Dr. Kerry Courneya.

  • Cancer is the second leading cause of death worldwide, claiming the lives of nearly 10 million people yearly. A recent study found that people who exercise regularly are nearly half as likely to die of cancer than those who are inactive.

    Researchers assessed the physical activity of more than 28,000 people diagnosed with stage 1 cancer in the year before their diagnosis based on data gathered from fitness devices, gym logs, and organized fitness events. They categorized the participants' activity as none, low (less than 60 minutes weekly), and medium to high (60 minutes or more weekly). Then, they measured their time to cancer progression and death rates.

    They found that participants with low physical activity were 16% less likely to experience cancer progression and 33% less likely to die than those who were inactive. However, those with medium to high activity levels were 27% less likely to experience progression and 47% less likely to die than those who were inactive.

    These findings highlight exercise’s protective role in reducing cancer progression and improving survival. Exercise boosts the body’s immune system, helping it to combat cancer. It also promotes shear—the frictional drag exerted by blood flowing against the inner walls of blood vessels. Shear damages cancer cells, driving their death. Learn more in this clip featuring Dr. Rhonda Patrick.

  • How fit you are may matter more than how much you weigh when it comes to your risk of dying early. A recent review and meta-analysis found that poor cardiorespiratory fitness increases the risk of early death from cardiovascular disease and other causes, regardless of body weight.

    Researchers analyzed the findings of 20 studies investigating the effects of cardiorespiratory fitness and body weight on the rates of early death from cardiovascular disease and all other causes. The various studies included nearly 400,000 participants and compared the risks among people who were overweight or obese to those who were normal weight.

    They found that overweight, fit people were about 50% more likely to die from cardiovascular disease and had roughly the same overall risk of early death as those with normal weight. Obese, fit people were 62% more likely to die from cardiovascular disease and had an 11% higher overall risk of early death, but these differences were not statistically significant.

    However, being unfit was linked to a much higher risk of death. Normal-weight people who were unfit were about twice as likely to die from cardiovascular disease and all causes. Overweight, unfit people had roughly 2.5 times the risk of cardiovascular death and 82% higher overall risk of early death. Obese, unfit people had more than triple the risk of cardiovascular death and twice the risk of dying from any cause compared to those with normal weight.

    These findings suggest that cardiorespiratory fitness robustly predicts the risk of early death from cardiovascular disease and other causes. Vigorous exercise, such as high-intensity interval training, is a great way to boost cardiorespiratory fitness and prevent early death. Learn more in this episode featuring Dr. Rhonda Patrick.

  • Creatine helps supply energy to muscles during high-intensity exercise and is commonly used to boost performance and muscle mass. However, determining the most effective creatine supplementation protocol has proven challenging. A recent study found that combining creatine with dextrose for five days rapidly increases muscle total creatine, with continued consumption maintaining this high level.

    Researchers provided healthy young men with one of four creatine supplementation protocols: Group 1: Four doses of 5 grams of creatine daily for five days, followed by 5 grams daily for 28 days.
    Group 2: Four doses of 5 grams of creatine plus 95 grams of dextrose daily for five days. Group 3: Split from Group 2 after the initial five days:
    Group 3A: 5 grams of creatine daily for 28 days.
    Group 3B: 5 grams of creatine plus 95 grams of dextrose daily for 28 days. Group 4: Four doses of 5 grams of creatine with 14 grams of protein, 7 grams of phenylalanine, 7 grams of leucine, and 57 grams of dextrose daily for five days, followed by a single daily dose of the same combination for the next 28 days.
    The researchers collected muscle biopsies from the participants at baseline, after five days, and after 33 days.

    They found that muscle total creatine increased in Groups 1, 2, and 4 after five days. The largest increase occurred in Group 2, reaching an average maximum of 150 mmol/kg. However, after 33 days:
    Group 1 total creatine increased further to approximately 150 mmol/kg.
    Group 3A showed a tendency to decline.
    Group 3B remained unchanged from the level observed at five days.
    Group 4 remained unchanged from the level observed at five days and was lower than Group 1. Creatine transporter gene expression changed slightly in all groups. However, the more creatine levels increased after five days, the smaller the change in this gene’s activity.

    These findings suggest that combining creatine with dextrose for five days rapidly increases total muscle creatine. Continued consumption of creatine with dextrose helps maintain this high level. While ingesting creatine alone also boosts total muscle creatine, it takes longer to reach levels similar to those in combination with dextrose. Learn more about creatine in this episode featuring Dr. Rhonda Patrick.

  • Muscle contraction, the hallmark of exercise, releases signaling molecules called myokines that influence cell function throughout the body. However, the mechanical forces it generates may also play a role. A recent lab study found that biochemical and mechanical signals from contracting muscle work synergistically to promote nerve growth and maturation.

    Researchers grew muscle cells on a specialized gel that mimicked the movements of contracting muscles. Then, by adding tiny magnetic particles, they stretched the cells to simulate exercise. They assessed how these forces and the myokines released by the muscle cells influenced the growth of nerve cells.

    They found that nerve cells grew and migrated more readily when exposed to myokines from contracting muscle cells, with more robust effects at higher levels of muscle activity. Stretching the nerve cells mechanically produced similar growth, but further analysis demonstrated that chemical signals were more effective in activating genes related to nerve growth and forming connections.

    These findings suggest that exercise influences nerve health through biochemical and mechanical pathways, providing new insights into how muscle activity supports the nervous system. Myokines also exert anti-cancer effects. Learn more in this episode featuring Dr. Rhonda Patrick.

  • Frailty isn’t just about getting older—it’s a key indicator of biological age that can signal an increased risk for many health concerns, including dementia. A recent study found that rapid increases in frailty increase the risk of dementia by as much as 73%, especially among females.

    Researchers analyzed data from four large studies involving nearly 88,000 adults aged 60 and older. They measured participants' frailty levels at the start and monitored their health, including the development of dementia, over several years.

    They found that in the years before dementia began to manifest, frailty tended to increase. Participants with the most rapid increases in frailty were 18% to 73% more likely to develop dementia than those with slower frailty progression. Frailty was more common in females than males among those who developed dementia, with the greatest differences seen in the years leading up to dementia onset.

    These findings suggest that measuring frailty could help identify people at greater risk for dementia, serving as an early target for strategies to reduce dementia risk through public health interventions and lifestyle changes. One powerful lifestyle approach for reducing dementia risk is exercise—especially the vigorous kind. Learn more in this episode featuring Dr. Rhonda Patrick.

  • Exercise can profoundly affect your brain, boosting memory and enhancing cognitive performance. But imagine if your daily exercise routine could boost your grandchildren’s brainpower. A recent study in mice found that cognitive benefits from physical activity can be passed down to future generations, even if they don’t exercise.

    Researchers compared the cognitive performance of male mice whose grandfathers exercised regularly with those whose grandfathers were sedentary. They also analyzed genetic markers related to brain function in both groups.

    Mice with active grandfathers had better memory recall, particularly in tasks requiring spatial (recalling locations) and non-spatial (recalling facts and events) memory. Although their cognitive abilities improved, these mice didn’t experience the new brain cell growth observed in the exercising grandfathers. Additionally, the researchers identified 35 microRNA molecules related to brain function, with two associated with poorer cognitive performance.

    microRNAs are small molecules that regulate gene activity by determining which proteins are produced in cells. They play a key role in many biological functions, including development, disease progression, and how cells respond to changes in their environment.

    These findings suggest that the cognitive benefits of exercise can be passed down to future generations. Check out the Cognitive Enhancement Blueprint—a members' only perk—to learn more about the effects of exercise on brain health and function.

  • If you’re struggling with exercise performance, your gut health might be partly to blame. The gut microbiota is critical for boosting exercise performance and regulating energy metabolism. A recent study found that mice without gut microbes, known as germ-free mice, had lower exercise capacity and used oxygen and glucose less efficiently during physical activity.

    Researchers compared germ-free mice to mice with normal gut bacteria. They fed both groups a regular diet and allowed them to exercise on running wheels. They measured the animals' body composition, oxygen and carbon dioxide usage, and glucose levels to assess how the absence of gut microbes affected exercise performance and energy use.

    They found that germ-free mice gained less weight, had lower fat mass, and had lower aerobic exercise capacity than mice with normal gut bacteria. Germ-free mice also exhibited reduced glucose storage and usage, impairing their capacity to fuel physical activity. Additionally, their fat tissue adapted by breaking down more fat, making them leaner and less prone to obesity, but at the cost of reduced energy availability during physical activity.

    These findings suggest that the absence of gut bacteria limits the body’s ability to store and use glucose, adversely affecting exercise performance. They also highlight gut microbes' vital role in supporting metabolism and physical endurance. Learn more about gut microbes' effects on metabolism in this clip featuring Dr. Michael Snyder.

  • Keeping our hearts strong and healthy becomes increasingly challenging as we age, especially for older women. However, physical activity, especially resistance training, may benefit the heart. A recent study found that a 24-week resistance training program improved heart function in older women.

    Researchers assigned 73 physically independent older women (average age, 68) to either an exercise training or sedentary group. The training group participated in a supervised resistance training program three times weekly for 24 weeks, using machines and free weights. Each session included exercises targeting the whole body, with three sets of eight to 12 repetitions each. The researchers measured the participants' cardiac function before and after the program.

    They found that women in the training group experienced several improvements in heart function, including: - A 10.6% decrease in left ventricular volume versus a 1.1% increase in the sedentary group. - A 9.1% decrease in left atrial volume versus a 3.9% increase in the sedentary group. - Better heart relaxation, indicated by a 4.8% reduction in the diastolic function index.

    These findings suggest that regular resistance training improves heart structure and function in older women, potentially reducing the risk of age-related cardiac decline. Finding the time for resistance training can be difficult, however. Listen as Drs. Brad Schoenfeld and Stuart Phillips describe time-efficient ways to incorporate resistance training into a busy schedule.

  • Study link:

    Athletes often warm up before a big race, but does heating your muscles make a difference? An early study found that warming muscles boosts performance by 11% during intense exercise—but at a cost.

    Researchers asked four young, healthy adults to perform 20-second high-intensity sprints on an exercise bike under four different muscle temperature conditions: room temperature, after leg immersion in hot water (44°C/111.2°F), and after immersion in cool water (18°C/64.4°F and 12°C/53.6°F). They measured the participants' muscle temperature and analyzed their peak force and power output during each sprint.

    They found that increasing muscle temperature using warm water immersion boosted peak force and power 11% more than resting at room temperature. In contrast, cooling the legs in 18°C (64.4°F) and 12°C (53.6°F) water decreased power output 12% and 21% more, respectively. However, higher muscle temperatures also led to quicker fatigue during the sprints. The beneficial effect of temperature was greater at higher pedaling speeds, with a 10% increase in power for every degree (1°C/1.8°F) increase in temperature at the fastest speed.

    It’s important to note that this was a small study that was conducted several years ago. However, the findings suggest that warming muscles before high-intensity exercise enhances power and performance, particularly at faster speeds. This benefit comes with a trade-off of earlier fatigue, potentially limiting endurance activity performance. Cooling, on the other hand, may reduce power output but could extend endurance by slowing the onset of fatigue.

    Interestingly, research shows that warming the body after exercise—in a sauna, for example—can boost performance. In contrast, cCooling the body after exercise may improve glucose and lipid metabolism, decrease inflammation, improve cognitive performance, and enhance immune function — possibly at the cost of reductions in hypertrophy. Learn more in this episode featuring Dr. Rhonda Patrick.

  • Smoking has numerous harmful effects on health, including increased risks of lung cancer, heart disease, and stroke. Evidence indicates smoking also contributes to cognitive decline, affecting memory and fluency. A recent study found that smoking accelerates cognitive decline by as much as 17% over time.

    Researchers examined data from more than 32,000 cognitively healthy adults aged 50 to 104 from 14 European countries. They grouped participants according to whether they smoked, engaged in regular exercise, were socially active, and drank moderately—defined as less than or equal to two alcoholic drinks per day for men or one drink per day for women. Then, they analyzed the effects of lifestyle on memory and fluency decline over 10 years.

    They found that non-smokers maintained relatively stable memory and fluency scores over the 10 years. However, smokers experienced up to 17 percent greater decline in memory and up to 16 percent greater decline in fluency, even after considering other factors that influence cognitive aging, including age at baseline, gender, country, education, wealth, and chronic conditions. Interestingly, healthy lifestyle behaviors offset some of the risks associated with smoking, with smokers who exercised, socialized, and drank moderately exhibiting cognitive declines comparable to non-smokers.

    These findings suggest that smoking markedly increases cognitive decline, increasing the risk for Alzheimer’s disease and other forms of dementia. Quitting smoking can be challenging, but mindfulness techniques can help. Learn more about mindfulness in this clip featuring Dr. Ashley Mason.

  • Muscle contraction relies on a magnesium-dependent calcium transport system. Consequently, magnesium levels drop after exercise, increasing muscle soreness and impairing performance. A recent review found that magnesium supplementation reduces muscle soreness, improves performance, and protects against muscle damage.

    Researchers reviewed the findings of four studies investigating the effects of magnesium supplementation on muscle soreness. The studies included 73 participants (60 males and 13 females) between the ages of 19 and 27. One study focused on muscle soreness, one on running performance, and two on team sports performance.

    They found that 350 milligrams of magnesium glycinate daily reduced muscle soreness and improved recovery after resistance training. Similarly, 500 milligrams of magnesium oxide and stearate taken daily for a week reduced muscle soreness in recreational runners with low dietary magnesium intake. Markers of muscle damage decreased in elite basketball players who took 400 milligrams of magnesium daily throughout the season. Competitive cyclists experienced similar effects at the same dose.

    These findings suggest that magnesium supports muscle health and performance in recreational and competitive athletes. The review’s authors posited that physically active people need 10% to 20% more magnesium than the recommended doses taken two hours before physical activity, even during the off-season. For more information about magnesium, check out our deep-dive podcast and our comprehensive overview article.

  • Cardiorespiratory fitness is a measure of the body’s aerobic capacity – the ability to deliver oxygen to skeletal muscles – during sustained physical activity. A 2009 meta-analysis found that people with low cardiorespiratory fitness were 70 percent more likely to die prematurely and 56 percent more likely to experience a heart or cardiovascular disease-related event.

    Researchers evaluated data from 33 studies examining connections between cardiorespiratory fitness and the risk of premature death from all causes (more than 102,000 participants) and combined heart disease and cardiovascular disease events (more than 84,000 participants). They used maximal aerobic capacity, measured in metabolic equivalent (MET) units, to estimate cardiorespiratory fitness. They grouped participants into three categories based on their cardiorespiratory fitness levels: low (<7.9 METs), intermediate (7.9-10.8 METs), and high (≥10.9 METs).

    They found that for each 1-MET increase in maximal aerobic capacity (equivalent to a 1-kilometer per hour increase in running/jogging speed), the risk of death from all causes and heart disease/cardiovascular disease events. Compared to participants with high cardiorespiratory fitness, those with low cardiorespiratory fitness were 70 percent more likely to die prematurely and 56 percent more likely to experience a heart disease/cardiovascular disease event. However, even intermediate cardiorespiratory fitness conferred substantial benefits. Compared to participants with intermediate cardiorespiratory fitness, those with low cardiorespiratory fitness were 40 percent more likely to die prematurely and 47 percent more likely to experience a heart disease/cardiovascular disease event.

    These findings demonstrate that having low cardiorespiratory fitness markedly increases one’s risk of dying prematurely or developing heart or cardiovascular disease. The most accurate way to assess cardiorespiratory fitness involves measuring maximal oxygen uptake, often referred to as VO2 max, during a graded exercise test in a laboratory, clinical, or research setting. However, online calculators, such as the World Fitness Level, can predict VO2 max based on various personal factors. Learn more about VO2 max and the World Fitness Level calculator in this episode featuring Dr. Martin Gibala.

  • Aerobic exercise has profound effects on the human body – including the skin. Now findings from a new study suggest that resistance training slows skin aging. Women who engaged in resistance training had thicker, more resilient skin than women who engaged in aerobic exercise alone.

    Researchers compared the effects of aerobic versus resistance training on skin aging in 56 sedentary, middle-aged women. The participants engaged in a twice-weekly supervised exercise program involving either aerobic or resistance training for 16 weeks. The researchers evaluated the participants' skin properties, body composition, and physical capacity before and after the intervention.

    They found that both types of training improved skin elasticity and structure, but only resistance training increased the thickness of the dermis, the inner layer of the skin. Resistance training also increased levels of biglycan, a protein that promotes wound healing and skin resilience via its interactions with collagen. The researchers also noted an increase in the expression of genes related to the skin cells' extracellular matrix.

    These findings suggest that resistance training enhances several aspects of skin health, slowing the effects of skin aging. They also highlight yet another way in which resistance training bolsters health. Learn about other strategies to promote healthy, resilient skin in this Aliquot featuring Dr. Rhonda Patrick.

  • Changes in brain function and connectivity often occur many years before the clinical manifestation of cognitive impairment and dementia. A new study shows that lifestyle modifications, including exercise, vitamin D intake, and cognitive training, improve functional brain connectivity in older adults with mild cognitive impairment.

    The study involved 120 older adults (ages 60 to 80 years) with mild cognitive impairment. The participants engaged in 30 minutes of cognitive training and 60 minutes of exercise three times a week for 20 weeks. Thirty-eight of the participants received vitamin D supplements, while the remainder received a placebo. Researchers measured the participants' functional brain connectivity using MRI before and after the interventions.

    They found that physical exercise alone, exercise combined with cognitive training, or exercise combined with both cognitive training and vitamin D supplementation increased functional brain connectivity in regions of the brain’s default mode network, including the hippocampus and angular gyrus.

    The default mode network is a collection of interconnected neural structures involved in attention and focus. Disturbances in default mode network connectivity are associated with poor working memory, reduced performance, and work-related productivity losses.

    This study’s findings suggest that lifestyle behaviors, particularly exercise, enhance functional brain connectivity, potentially staving off age-associated cognitive decline. Learn more about the effects of exercise on the brain in this episode featuring Dr. Axel Montagne.

  • Running may be as effective as traditional antidepressant therapies for reducing symptoms of depression.

    A new study found that running was as effective as traditional antidepressant drugs at reducing symptoms of depression. In addition, people who ran had better physical health than those who did not.

    The study involved 141 people with depression. Participants chose which 16-week therapy intervention they preferred: running at least twice a week with a group (96 participants) or taking traditional antidepressant medication (45 participants). They underwent mental and physical health assessments before and after the interventions.

    The two therapies were comparable in terms of reducing depressive symptoms. However, running therapy improved many aspects of the participants' health, including body weight, waist size, blood pressure, heart rate, and heart rate variability.

    Nearly 25 million adults living in the United States take some form of antidepressant medication. Most antidepressants work by altering the brain’s chemistry to affect mood. Side effects of the drugs include nausea, weight gain, decreased libido, and anxiety, among others. Evidence suggests that antidepressants are only about 20 to 30 percent more effective at reducing symptoms of depression than placebo treatments.

    Exercise boosts the production of molecules that enhance mood and promote mental health. Learn more about the mental health effects of exercise in this video featuring Dr. Rhonda Patrick.

  • A new study shows that replacing sedentary time with physical activity improves sleep in women. Women who swapped just one hour of sedentary time or low-intensity activity with moderate- or vigorous-intensity activity slept better and felt more rested.

    Researchers investigated the effects of replacing sedentary time with physical activity. The study involved 683 men and women between the ages of 40 and 64 years. The participants wore accelerometers to gauge their activity levels for one week and reported their sleep quality.

    The researchers found that sleep measures improved when women replaced sedentary behavior or low-intensity physical activity with moderate- to vigorous-intensity physical activity. Interestingly, they found no associations between altering men’s activity levels and sleep quality, highlighting the sex-related differences in response to exercise.

    These findings indicate that engaging in moderate- to vigorous-intensity physical activity improves sleep quality in middle-aged women. They also align with other studies that show that exercise improves sleep. Sleep is essential for human health. Learn more about the benefits of sleep in this episode featuring Dr. Matthew Walker.

  • Aerobic exercise pre-conditions muscles for optimal returns from resistance exercise.

    Skeletal muscle contains a designated population of adult stem cells called satellite cells. These cells are typically inactive, but if the muscle is injured or stressed (as in exercise), they can be recruited to participate in the regeneration of muscle fibers. As such, satellite cells play important roles in muscle maintenance, repair, and hypertrophy, the increase in muscle size that accompanies exercise. Findings from a new study suggest that engaging in aerobic exercise prior to resistance training increases satellite cell numbers and promotes muscle hypertrophy via increased muscle capillarization.

    Muscle capillarization refers to the formation of capillaries in muscle tissue. Capillarization facilitates the delivery of oxygen, nutrients, and various signaling and growth factors to muscle tissues and plays critical roles in muscle maintenance and growth. Previous research indicates that muscle capillarization decreases with age.

    The study involved 14 healthy, recreationally active young adults (average age, 22 years). Using a specially adapted exercise bike that challenged only one leg, participants engaged in 45 minutes of progressively difficult aerobic exercise conditioning three times a week for six weeks. Previous research has demonstrated that six to eight weeks of conditioning is sufficient to promote muscle capillarization.

    Two weeks after completing the conditioning program, the participants began a 10-week resistance training program using both legs and primarily targeting the muscles of the thighs. Immediately after each resistance training session, participants received a whey protein supplement that contained leucine, a branched-chain amino acid that promotes muscle protein synthesis, which is essential for muscle gains. The investigators collected muscle tissue samples from the participants' legs before and after the interventions to assess muscle capillarization, fiber size, and satellite cell content and activity.

    They found that aerobic conditioning promoted muscle capillarization in the conditioned leg, amplifying muscle hypertrophy in response to resistance training. They noted that the number of satellite cells increased in the conditioned leg relative to the non-conditioned one. In addition, they observed a significant relationship between the degree of capillarization and hypertrophy.

    These findings suggest that engaging in aerobic exercise prior to resistance training promotes muscle capillarization, which in turn increases satellite cell numbers and promotes muscle protein synthesis and hypertrophy. Learn about other factors that promote muscle hypertrophy in this episode featuring Dr. Stuart Phillips.

  • Older adults who engage in leisure time physical activities have lower risk of premature death.

    Leisure time physical activity is a broad term that refers to physical activities performed outside work or typical household responsibilities. Examples include exercise, sports, dancing, gardening, and walking. Findings from a recent study suggest that certain leisure time physical activities are associated with a lower risk of death from all causes of premature death, including cardiovascular disease and cancer, in older adults.

    Most public health organizations recommend that adults of all ages should engage in at least 150 minutes of moderate-intensity aerobic physical exercise or at least 75 minutes of vigorous-intensity aerobic physical exercise each week, or an equivalent combination of both. The bulk of the research focused on the benefits of physical activity has been in younger people, the findings of which might not be translatable to older adults.

    The investigators drew on data from 272,500 older adults (average age, 70 years) enrolled in the National Institutes of Health-AARP Diet and Health Study, an ongoing study of associations between diet and cancer. Participants provided information about their demographics, height, weight, smoking status, mood, educational level, and alcohol consumption. They also answered questions about the average amount of time they spent per week during the previous year engaging in cycling, swimming laps, playing racquet sports, playing golf, walking for exercise, jogging or running, and other aerobic exercises. The investigators calculated the participants' average leisure time activity levels in terms of metabolic equivalents, or METs, a measure of the rate of energy expended per unit of time.

    They found that playing racquet sports was associated with a 16 percent reduction in the risk of death from any cause and running was associated with a 15 percent reduction. The other activities conferred protection as well, but to a lesser extent. Achieving the recommended amount of physical activity through any combination of the seven leisure time activities reduced the risk of death by 13 percent. The protective effects of leisure time physical activity were dose-dependent to a degree, with greater duration conferring greater reduction in risk, but levels beyond those recommended showed diminishing returns.

    These findings suggest that older adults who meet physical activity guidelines through leisure time physical activities, especially aerobic activities such as racquet sports or running, have a reduced risk of premature death from all causes. Learn about the benefits of aerobic exercise in our overview article.

  • Exercise boosts mitochondrial function and promotes weight loss among people who struggle to lose weight with dieting alone.

    Most weight loss programs focus on reducing caloric intake. Although this strategy works for many people, a subset of people with obesity are diet-resistant – failing to lose weight even when adhering to a low-calorie diet. Findings from a new study suggest that exercise promotes weight loss in diet-resistant women by boosting mitochondrial function.

    Mitochondria are tiny cellular organelles that produce energy in the presence of oxygen. They are often referred to as the “powerhouses of the cell” because of their role in the production of ATP. Mitochondrial dysfunction, the disruption of normal mitochondrial function that occurs over time, is a driver of many chronic diseases, such as cancer, type 2 diabetes, and cardiovascular disease, and is a hallmark of aging.

    The investigators enrolled 20 women with obesity for the study. Half of the women had exhibited diet resistance when following a 900-calorie-per-day diet, while the other half had exhibited diet sensitivity. Both groups participated in a supervised, six-week exercise program that included both aerobic and resistance exercises, performed three times per week. The investigators assessed the women’s body composition and metabolic markers and collected muscle tissue samples for biopsy.

    They found that at the end of the six-week exercise program, the women who were diet resistant exhibited improved body composition and muscle metabolism and increased numbers of muscle mitochondria. The exercise program elicited only minimal effects in women who were diet sensitive. Interestingly, the diet-sensitive women exhibited risk factors associated with metabolic syndrome, suggesting that diet-sensitive obesity confers a greater risk for cardiometabolic disease.

    These findings demonstrate that exercise promotes weight loss and metabolic health in women with obesity and diet resistance and may confer greater health benefits than rapid diet-induced weight loss. Learn more about the benefits of exercise in our overview article.

  • Exercising 30 minutes a day reduces the risk of a ruptured brain aneurysm.

    Exercise and other forms of physical activity exert profound cardioprotective effects. In fact, people who regularly engage in moderate leisure time physical activity are less likely to develop cardiovascular disease than people who are inactive. Findings from a 2019 study suggest that just 30 minutes of moderate exercise daily reduces the risk of experiencing a ruptured brain aneurysm.

    The bleeding associated with a ruptured brain aneurysm impedes the delivery of oxygen to brain tissue, potentially causing a stroke and impairing cognitive and motor function. Experts estimate that as many as 12 percent of people who experience a ruptured brain aneurysm will die immediately; as many as 45 percent will die within 30 days of the event.

    The study involved more than 65,000 adults enrolled in the FINRISK, an ongoing study of risk factors for chronic diseases among people living in Finland. The investigators collected information about the participants' physical activity, including activities performed during leisure time, commuting, and working. They also reviewed medical records and autopsy registries to identify those who had experienced a ruptured brain aneurysm.

    They found that 543 of the participants experienced a ruptured brain aneurysm during a 42-year period. However, those who engaged in regular physical activity were protected: For every 30-minute increase in weekly leisure-time physical activity, the risk of experiencing a ruptured brain aneurysm decreased by 5 percent. The protective effects of leisure-time activity were observed across all age groups and were particularly strong for smokers. Participants who had an active commute were protected as well, but this protection lessened upon retirement, when they stopped commuting. Interestingly, those who had moderate or high work-related physical activity were 34 to 41 percent more likely to experience a ruptured brain aneurysm.

    These findings suggest that just 30 minutes of moderate leisure-time exercise and physical activity daily exert robust cardioprotective effects, reducing the risk of ruptured brain aneurysm. Learn more about the benefits of exercise in our overview article.

  • From the article:

    Calculating population attributable risk – the fraction of subarachnoid hemorrhages that can be attributed to a particular trigger factor – the researchers identified the eight factors and their contribution to the risk as:

    -Coffee consumption (10.6 percent)

    -Vigorous physical exercise (7.9 percent)

    -Nose blowing (5.4 percent)

    -Sexual intercourse (4.3 percent)

    -Straining to defecate (3.6 percent)

    -Cola consumption (3.5 percent)

    -Being startled (2.7 percent)

    -Being angry (1.3 percent)

    “All of the triggers induce a sudden and short increase in blood pressure, which seems a possible common cause for aneurysmal rupture,” said Monique H.M. Vlak, M.D., lead author of the study and a neurologist at the University Medical Center in Utrecht, the Netherlands.

    Risk was higher shortly after drinking alcohol, but decreased quickly, researchers said.

    […]

    Although physical activity had triggering potential, researchers don’t advise refraining from it because it’s also an important factor in lowering risk of other cardiovascular diseases.

    “Reducing caffeine consumption or treating constipated patients with unruptured IAs with laxatives may lower the risk of subarachnoid hemorrhage,” Vlak said. “Whether prescribing antihypertensive drugs to patients with unruptured IAs is beneficial in terms of preventing aneurysmal rupture still needs to be further investigated.”

    View publication

  • Cardiorespiratory fitness helps prevent age-related brain volume losses.

    The brain loses about 5 percent of its volume every decade after the age of 40 years, likely due to the death of neurons in the gray matter. These losses contribute to age-related cognitive decline and loss of neuroplasticity, the brain’s ability to change and adapt to new exposures. Findings from a 2020 study suggest that having greater cardiorespiratory fitness helps prevent age-related brain volume losses.

    Cardiorespiratory fitness is a measure of the body’s aerobic capacity – the ability to deliver oxygen to skeletal muscles – during sustained physical activity. Poor cardiorespiratory fitness, along with dyslipidemia, family history, hypertension, age, cigarette smoking, diabetes mellitus, obesity, and physical inactivity, increases a person’s risk for cardiovascular disease and death. The most accurate way to assess cardiorespiratory fitness involves measuring maximal oxygen uptake, often referred to as VO2 max, during a graded exercise test in a laboratory, clinical, or research setting.

    The study involved more than 2,000 healthy adults (average age, 52 years) who were enrolled in a larger, ongoing study. The investigators measured the participants' cardiorespiratory fitness, assessed via VO2 max while riding on an exercise bike. They collected the participants' demographic data, and they measured their brain volumes via magnetic resonance imaging scans.

    They found that participants with greater cardiorespiratory fitness tended to have greater gray matter and total brain volumes. They also had more clusters of gray and white matter tissue in brain areas responsible for cognitive function rather than movement. These findings held true even when taking the participants' ages, education levels, smoking status, blood pressure, and body weights into consideration.

    These findings suggest that having greater cardiorespiratory fitness ameliorates some of the brain volume losses associated with aging and underscore the importance of exercising throughout the lifespan. Learn more about the health benefits of exercise in our overview article.

  • Aerobic exercise influences many aspects of human health, including brain health. For example, exercise promotes the release of brain-derived neurotrophic factor, better known as BDNF, a cell-signaling protein that influences the formation, growth, survival, and development of neurons. Findings from a 2020 study suggest that exercise intensity determines which parts of the brain are affected during a workout.

    Exercise intensity is defined as how hard the body works during exercise. During low-intensity aerobic exercise, a person’s heart rate is typically maintained at a steady pace of about 50 percent of its maximum ability, and workouts last for at least 30 minutes. During high-intensity aerobic exercise, a person’s heart rate is typically 75 percent of its maximum ability or higher. For example, high-intensity interval training, often referred to as HIIT, is a popular form of high-intensity exercise involving short bursts of intense aerobic exercise interspersed with periods of rest or lower-intensity exercise. During a typical HIIT session, exercisers typically achieve 80 to 100 percent of their VO2max (a measure of respiratory function) or maximum heart rate. Most HIIT workouts are brief, lasting just 15 to 30 minutes.

    The study involved 25 healthy male athletes who engaged in both low-intensity and high-intensity aerobic exercise sessions on a treadmill. The sessions lasted for approximately 30 minutes and were separated by at least two days. The participants underwent a battery of tests to determine their mental state, cognitive performance, and attention. Before and after the exercise sessions, they underwent resting-state functional magnetic resonance imaging (rs-fMRI), a technique that characterizes the functional connectivity of neuronal networks when the brain is at rest.

    The investigators found that the participants' moods improved after both exercise intensities. However, the rs-fMRIs revealed that the different intensities affected different parts of their brains. The low-intensity exercise turned on the activity of brain networks involved in cognitive function and attention processing. On the other hand, the high-intensity exercise turned on networks involved in mood and emotions and turned off networks involved in motor function.

    These findings suggest that differing exercise intensities affect different parts of the brain during exercise and underscore the importance of varying workout programs. Learn more about the effects of aerobic exercise on health in our overview article.

  • Exploiting the “gravitostat,” a novel homeostatic mechanism that regulates body weight, promotes weight loss.

    Having overweight or obesity increases a person’s risk of developing many chronic diseases. But losing weight loss is challenging, partly due to homeostatic mechanisms that regulate body weight. Findings from a 2020 study suggest that exploiting a novel homeostatic weight-regulating mechanism called the gravitostat promotes weight loss in humans.

    The concept of the gravitostat first emerged in 2017, when scientists implanted small weights into the abdomens of mice and found that the animals’ food intake decreased, promoting weight loss and improving glucose tolerance. They suggested that the gravitostat regulates weight via a negative feedback system involving bone cells called osteocytes. Because osteocytes can sense changes in bone strain, the investigators proposed that increasing the animals’ body weight activated a biological sensor that communicated with the osteocytes of weight-bearing bones to drive changes in eating behaviors and subsequent weight loss.

    In the 2020 study, the investigators conducted a randomized controlled trial involving 69 adults with mild obesity (body mass index of 30-35). About half of the participants wore a heavy weighted vest (11 percent of their body weight) for eight hours every day for three weeks, while the other half wore a light vest (1 percent of their body weight). Before and after the intervention, the investigators weighed the participants and analyzed their body composition using bioelectrical impedance.

    They found that participants who wore the heavy vest lost an average of 1.37 percent more bodyweight than those who wore the light vest, translating to about 3.5 pounds. Those who wore the heavy vests also lost fat mass and gained fat-free mass. These findings suggest that the gravitostat regulates body weight in humans and exploiting it provides a possible strategy for losing weight.

    Overcoming other aspects of bodyweight homeostasis might still prove challenging, however. Research from Dr. Eran Elinav’s lab suggests that metabolic parameters normalize with weight loss, but characteristics of the microbiome remain unchanged. In other words, the microbiome holds a memory of past obesity that promotes weight regain. Preclinical studies indicate that repeated weight cycling shifts gut microbes to a configuration with an altered ability to metabolize flavonoids — compounds that usually help promote the burning of excess energy by adipose tissue. Learn more in this clip featuring Dr. Eran Elinav.

  • Exercise activates the endocannabinoid system to promote learning and memory formation.

    Scientists have identified robust links between physical exercise and brain health. Some of the mechanisms that drive the beneficial effects of exercise on the brain include increases in brain volume and connectivity, improved blood flow, enhanced synaptic plasticity, and increased neurogenesis – the formation of new neurons. Findings from a 2020 study suggest that moderate- to vigorous-intensity exercise improves motor sequence memory via endocannabinoid action on the hippocampus.

    Motor sequence memory involves learning predefined sequences of interrelated motor actions, such as playing the piano or dancing. The hippocampus interacts with various neural networks to support the formation of motor sequency memory.

    Endocannabinoids are small lipid molecules produced in the body that bind to cannabinoid receptors in the central and peripheral nervous systems. Endocannabinoids regulate many physiological processes, including movement control, pain processing, brain development, and learning and memory. The two major endocannabinoids in the body are anandamide and 2-arachindonyl glycerol.

    The study involved 15 healthy adults (average age, 23 years) who had at least fair respiratory fitness, as measured via VO2 max. Participants completed a serial reaction time task (a widely used measure of learning and memory) before and after three conditions: moderate-intensity exercise, vigorous-intensity exercise, and rest. Prior to performing the task, participants consumed a standardized carbohydrate-rich breakfast. During the task, the investigators measured the participants' behavior, brain activity, and circulating anandamide (endocannabinoid) levels.

    They found that vigorous-intensity exercise markedly improved motor sequence memory compared to rest. Moderate-intensity exercise also improved motor sequence memory, but to a lesser degree. The improvements coincided with increased levels of the endocannabinoid anandamide and enhanced hippocampal activity.

    These findings suggest that vigorous-intensity exercise promotes motor sequence memory and learning and underscore the benefits of exercise on cognitive function. Learn about the beneficial effects of aerobic exercise in our overview article.

  • Lifelong exercise protects older adults from losing muscle mass and function with age.

    With age, muscles shrink in size and lose strength, a process called sarcopenia that can increase frailty and reduce the quality of life for older adults. In people with sarcopenia, muscle fibers contain fewer satellite cells (i.e., muscle stem cells) and progressively lose their connections to nerves, a process called denervation. Findings of a new report show that lifelong exercisers have more youthful muscles that resist denervation.

    Satellite cells are stem cells that proliferate, fuse together, and form the long tubular structures than comprise muscle fibers. Satellite cells are necessary for muscle repair and growth after exercise, a process called hypertrophy, due to their connection with cells that produce growth factors and deliver nutrients. Previous research demonstrates that exercise interventions that last several weeks can reverse muscle denervation in older adults with frailty; however, the preventive effects of lifelong exercise have yet to be investigated.

    The authors recruited 15 moderately active young men (average age, 26 years), 16 older men who were lifelong exercisers (average age, 73 years), and 15 older men who lived a sedentary lifestyle (average age, 73 years). On their first visit to the lab, participants completed a bout of heavy resistance training on only one side of their body so that the researchers could compare the effects of exercise and sedentary behavior in each person. The researchers also measured maximum muscle strength and body composition and collected a blood sample. Participants provided another blood sample two days and six days after the exercise challenge and provided a muscle biopsy sample six days after.

    Lifelong exercisers had muscles that were more resistant to fatigue during exercise compared to sedentary young and older adults. Compared with sedentary older adults, lifelong exercisers had more satellite cells in their muscles connected to type 2 myofibrils, which are important for fast-twitch muscle movement, but no difference in connection to type 1 slow-twitch myofibrils. Muscles from lifelong exercisers also expressed high levels of mRNA for acetylcholine receptors, which are necessary for preventing denervation.

    These results show that lifelong exercisers maintained a more youthful muscle profile due to increased connections with muscle- and nerve-supporting satellite cells. People who started life with a sedentary lifestyle can still reap the longevity-promoting benefits of exercise. Starting a new aerobic exercise habit, even at age 70, cuts heart disease death in half.

  • Endurance and resistance training are associated with distinct hormonal signatures Exercise is widely accepted to be beneficial to our health. Research finds it to have a positive dose-dependent impact on factors varying from cognitive function and bone strength to all-cause mortality and metabolic health. But does the specific mode of exercise make a difference? A 2018 study suggests that resistance and endurance exercise engage largely distinct hormonal responses in the body. It also highlights endurance training as a particularly useful tool for engaging biochemical signals that can help combat substance addiction.

    To compare resistance and endurance training, researchers recruited ten healthy young men (average age 24 years) to participate in a cross-over study. This meant that each participant engaged in both forms of exercise, with half randomly selected to first perform a one-hour endurance training session before “crossing over” to one resistance training session after a 6-to-12-day rest period. The other half of the participants followed the reverse order.

    Training sessions were individually tailored to ensure equivalent levels of physiological stress across participants. For instance, resistance training sessions required participants to complete five sets of 10 reps for each exercise, at resistance levels corresponding to 90 percent of their 10 rep maximum capacity. The endurance training sessions were designed to make participants work at 70% of their VO2max(i.e. maximum oxygen uptake capacity). Importantly, participants exercised 10 hours after receiving controlled meals to prevent nutritional factors from interfering with hormone levels in their blood, which was drawn immediately before and at several timepoints after exercise.

    The experiment revealed some surprising insights into the hormonal pathways engaged by the two forms of exercise. Shortly after resistance training, participants had lower plasma levels of fibroblast growth factor 19 (FGF19) – a protein secreted by the small intestine and implicated fighting metabolic disease by stimulating the formation of metabolically active brown fatty tissue and increasing sensitivity to the satiety hormone leptin. The drop in FGF19 shortly after resistance exercise is somewhat counterintuitive given robust links between strength training and metabolic health. It raises questions about a potential long-term rebound increase following recovery, which our team looks forward to seeing explored in future studies.

    Endurance exercise engaged a distinct biochemical pathway. It caused a near-triple increase in the pancreatic hormone glucagon, which stimulates the release of glucose and fatty acids into the blood. This glucagon spike was followed by an increase in plasma fibroblast growth factor 21 (FGF21) – a metabolic regulator implicated in processes ranging from fatty acid oxidation and ketone body production to the regulation of appetite for addictive substances like alcohol. The findings suggest that endurance and resistance training are associated with distinct hormonal and metabolic benefits, and that endurance exercise in particular may be a helpful strategy in combating addiction.

    Link to full study

  • Liver-derived hormone FGF21 dramatically reduces appetite for alcohol Researchers believe that humans first encountered alcohol long before we learnt how to control the process and make it ourselves – through the consumption of fermented fruit. One plausible result of this long history of alcohol exposure is that we have evolved a suite of biological mechanisms for detoxifying and regulating our appetite for alcohol, which may be useful for developing new treatments for alcohol use disorder. Now, a recent randomized controlled trial suggests that the liver-derived hormone fibroblast growth factor 21 (FGF21) is a candidate treatment capable of altering the reward system of the brain and profoundly reducing alcohol intake in primates.

    The researchers carried out their study in vervet monkeys – a species that parallels human populations in containing a mix of alcohol avoiders, moderate consumers, and heavy consumers who will drink to the point of intoxication. Twenty monkeys were selected based on having at least a slight interest in consuming alcohol. The researchers then quantified each individual’s preferred alcohol intake level by monitoring their behaviours when the animals received four hours of daily access to a bottle of 10% ethanol solution alongside plain tap water.

    After a baseline observation period of nine days, monkeys were randomly selected to receive a daily injection of either a sterile saline solution (placebo) or a pharmacological analog of the liver hormone FGF21 for a total of 16 days.

    The FGF21-mimicking drug was found to produce a 50 percent reduction in alcohol consumption, without influencing the monkeys’ intakes of food or water. Looking into the effects of FGF21 in the brain, the researchers uncovered that both FGF21 and its synthetic analog increased the transmission of signals to a specific group of brain cells in the nucleus accumbens – a hotspot of the brain’s reward system. These cells were distinguished by the presence of specifically D2-type dopamine receptors, which have been strongly implicated in reigning in impulsive and repetitive consumption of other substances like sugar. Human variants in the D2 receptor gene have also been linked to greater risk of alcohol dependence.

    The findings suggest that FGF21 serves as a regulatory message between the liver and the brain’s impulse control circuits, and that boosting this signal may aid in the treatment of substance addictions.

    -Link to full publication.

  • Just 20 minutes of exercise daily reduces heart disease risk in older adults. The benefits of regular physical exercise on cardiovascular health are well established. However, most studies investigating the benefits of exercise have been conducted in younger adults rather than older ones, for whom cardiovascular disease risk is greatest. Findings from a recent study demonstrate that 20 minutes of exercise daily reduces the risk of cardiovascular disease in older adults.

    The authors of the study drew on data from the Progetto Veneto Anziani, a long-term cohort study of more than 3,000 older adults (65 years and older) living in northern Italy. They identified participants with cardiovascular disease based on information gleaned from medical exams or hospital records. Every five years (at 65, 70, 75, 80, and 85 years of age), the authors assessed the participants' physical activity levels based on information provided in questionnaires.

    The risk of cardiovascular-related events or premature death was lower among older adults who were physically active. Men, in particular, were half as likely to experience a cardiovascular event if they were physically active. The effects of exercise were dose-dependent, with 20 minutes of moderate- to vigorous-intensity exercise daily providing the greatest benefits, especially when performed earlier in one’s later years, between the ages of 70 and 75 years. Exercising more than 40 minutes daily provided no additional benefits.

    Although the authors of this study did not differentiate between the effects of different types of exercise, their findings demonstrate that aerobic exercise is particularly beneficial for cardiovascular health. Learn more about aerobic exercise in our overview article.

  • Curcumin is the principal bioactive compound present in the yellow spice turmeric. An abundance of scientific evidence indicates that curcumin has antioxidant, anti-inflammatory, anticancer, and neuroprotective properties in humans. Findings from a 2019 study suggest that curcumin improves exercise tolerance in mice with heart failure via its activation of Nrf2.

    Heart failure, commonly referred to as the end stage of heart disease, affects more than 26 million people worldwide. Exercise intolerance is a common feature of heart failure and is typically attributed to low ejection fraction – a measure of ventricular efficiency. A critical driver of low ejection fraction is oxidative stress.

    Nrf2 is a cellular protein that regulates the expression of antioxidant and stress response proteins via participation in the Keap1-Nrf2-ARE biological pathway. Nrf2 activates the transcription of cytoprotective proteins that protect against oxidative stress due to injury and inflammation.

    The study investigators gauged the effects of curcumin in mice that had heart failure with reduced ejection fraction and in mice with healthy hearts. A subset of the mice received daily curcumin supplementation, while the others did not. The investigators measured the animals' heart function via echocardiogram, assessed their exercise performance on a treadmill, and measured the expression of Nrf2 and its target proteins in their muscles.

    They found that both groups of mice that received curcumin (including those with healthy hearts) had improved exercise capacity compared to those that did not receive the compound. They also found that Nrf2 expression and antioxidant proteins increased in the mice with heart failure that received curcumin.

    These findings suggest that impaired Nrf2 drives oxidative stress in skeletal muscle in those who have heart failure with low ejection fraction. Curcumin counters these effects by upregulating antioxidant defenses in skeletal muscle, likely mediated by Nrf2 activation. Many plant-based dietary compounds induce Nrf2 activity, including sulforaphane, a compound derived from broccoli and broccoli sprouts. Learn more about Nrf2 and sulforaphane in this episode featuring Dr. Jed Fahey.

  • From the article:

    In a new study published in the scientific Journal of Clinical Investigation – Insight, the researchers show that cardio training on an exercise bike causes three times as large an increase in the production of the hormone FGF21 than strength training with weights. FGF21 has a lot of positive effects on metabolism.

    […]

    Endurance training on a bicycle has such a marked effect on the metabolic hormone that we know ought to take a closer look at whether this regulation of FGF21 is directly related to the health-improving effects of cardio exercise. FGF21’s potential as a drug against diabetes, obesity and similar metabolic disorders is currently being tested, so the fact that we are able to increase the production ourselves through training is interesting', Christoffer Clemmensen elaborates.

  • From linked article:

    The researchers gave the monkeys a two-bottle choice between water and ethanol, and administered one group an analog of FGF21 to see what effect it had. Sure enough, the test monkeys drank 50 percent less alcohol than the control group. Similar tests in mice also saw a 50-percent reduction in alcohol consumption after being given either human FGF21 or an analog. Interestingly though, the mice and monkeys still chose the ethanol just as often as before, but they drank far less each time.

    Fibroblast growth factor 21 happens to be modulated by aerobic exercise:

    In a new study published in the scientific Journal of Clinical Investigation – Insight, the researchers show that cardio training on an exercise bike causes three times as large an increase in the production of the hormone FGF21 than strength training with weights. FGF21 has a lot of positive effects on metabolism.

  • From the article:

    Researchers from the Morrison laboratory discovered that forces created from walking or running are transmitted from bone surfaces along arteriolar blood vessels into the marrow inside bones. Bone-forming cells that line the outside of the arterioles sense these forces and are induced to proliferate. This not only allows the formation of new bone cells, which helps to thicken bones, but the bone-forming cells also secrete a growth factor that increases the frequency of cells that form lymphocytes around the arterioles. Lymphocytes are the B and T cells that allow the immune system to fight infections.

    When the ability of the bone-forming cells to sense pressure caused by movement, also known as mechanical forces, was inactivated, it reduced the formation of new bone cells and lymphocytes, causing bones to become thinner and reducing the ability of mice to clear a bacterial infection.

  • Exercise oncology is an emerging branch of medicine that studies the application of exercise medicine in the treatment of cancer. Although there is a strong base of epidemiological research that supports a relationship between increased physical activity and decreased cancer severity and death, the molecular mechanisms that underlie this relationship require further research. Findings of a recent report identify myokines that suppress tumor growth in patients with prostate cancer.

    Myokines are molecules released from muscle cells that signal to non-muscle tissues that the body is physically active. Studies in non-human animals have shown that myokines such as oncostatin M, decorin,, and interleukin (IL)-6 suppress cancer growth; however research in humans is lacking.

    The investigators recruited 10 men (average age, 73 years) with prostate cancer who were undertaking androgen deprivation therapy, which includes drugs that block the action of testosterone and other male hormones. Participants completed 12 weeks of exercise training that included three sessions-per-week of supervised resistance training and daily self-directed moderate-to-vigorous physical activity. The investigators measured the participants' muscle strength, body composition, and serum myokine concentration before and after the exercise training intervention. They also grew prostate cancer cells in vitro, exposed them to serum from participants taken before and after exercise training, and observed the effects on cancer cells directly.

    Participants lost about six pounds of fat and eight pounds of total body weight during the intervention period. Participants significantly increased their strength, measured during the leg press (57 pound increase) and chest press (16 pound increase). Serum concentrations of oncostatin M increased by 82 percent while other myokines did not increase or could not be measured. Finally, prostate cancer cells incubated with serum taken post-exercise training reduced cancer growth by 22 percent compared to serum taken prior to exercise training.

    These results show that exercise induced the expression of myokines with tumor-suppressing ability in patients with prostate cancer. Future research is needed to refine the prescription of intensity, frequency, and type of exercise in cancer treatment.

  • The euphoria known as a “runner’s high” is caused by activation of the endocannabinoid system, a complex signaling system that regulates energy metabolism, inflammation, pain, and brain biology. The gut microbiota, which coordinates its activity with the brain and immune system, also modulates energy metabolism and inflammation and brain functions such as mood and cognition. Findings of a new report suggest that the endocannabinoid system is involved in communication between the gut and the immune system.

    The gut microbiota, the community of microorganisms that live in the digestive tract, consume nutrients from the diet that are not absorbed by the host and produce multi-purpose compounds such as short chain fatty acids (SCFA). Previous research has demonstrated that some strains of bacteria that produce SCFAs modulate the number of cannabinoid and opioid receptors in the gut. A dysregulated endocannabinoid system and gut microbiota may increase the risk of inflammatory bowel disease, irritable bowel syndrome, and obesity; however, [exercise may improve microbiota and gut health.](​​https://www.hindawi.com/journals/omcl/2017/3831972/)

    The authors collected baseline data from a group of 78 participants (age, greater than 45 years) with osteoarthritis who were part of a separate trial. They also collected data from a group of 40 additional adults. Participants provided a stool sample for the measurement of cannabinoids and cannabinoid metabolites, inflammatory markers, and SCFAs. They also sequenced the bacterial DNA contained in the stool sample to identify the types of bacteria present.

    The researchers found that endocannabinoid concentrations in the stool increased as levels of SCFAs, SCFA-producing bacteria, and overall microbiota diversity increased. Higher endocannabinoid levels were associated with higher levels of inflammation-resolving cytokines such as interleukin-10 and lower levels of pro-inflammatory cytokines such as interleukin-6 and tumor necrosis factor-alpha. Using a statistical model, the researchers found that endocannabinoid levels mediated the relationship between SCFA and inflammatory markers. This means that the relationship among these three variables is stronger than the relationship between SCFA and inflammatory markers alone.

    These results demonstrate that endocannabinoids facilitate some of the anti-inflammatory effects of SCFAs and that the endocannabinoid system modulates the immune system through activity of the gut microbiota.

  • Exposure to high heat while sauna bathing causes mild hyperthermia – an increase in the body’s core temperature – that induces a thermoregulatory response to restore homeostasis and condition the body for future heat stressors. These adaptations to high temperatures involve increased production of brain derived neurotrophic factor (BDNF), a promoter of neuroplasticity, and irisin, a biomarker of exercise. Findings of a new report demonstrate that whole-body hyperthermia increases BDNF and irisin in healthy young adults.

    Whole-body hyperthermia is a therapeutic strategy used to treat various diseases, including cancer and depression. Previous research has shown that use of a hyperthermia chamber increases BDNF to a greater extent than light intensity exercise. Some research has suggested that BDNF production is stimulated by irisin, a hormone secreted from muscle in response to exercise. Irisin may mediate some of the beneficial effects of exercise and sauna use in humans, but additional research is needed.

    The authors recruited 20 male participants (average age, 22 years) and assessed their baseline heat tolerance using a hyperthermia protocol. Participants reclined in a hyperthermia chamber while the researchers increased the temperature of the chamber by 50 degrees F every ten minutes until the participant reached their personal heat threshold. Next, participants completed ten hyperthermia sessions tailored to their baseline conditioning, during which the hyperthermia chamber was set to a temperature of 150 to 175 degrees F. Following a three-week wash-out period, they completed ten sham treatments over two weeks, during which the hyperthermia chamber was set to a temperature of 75 to 77 degrees F.

    Participants had an average core body temperature of 102 degrees F at the end of each whole-body hyperthermia treatment. Following ten whole-body hyperthermia treatments, participants had a significant increase in circulating irisin levels (6.3 micrograms per milliliter) compared to their baseline levels (5.0 micrograms per milliliter) and compared to their irisin levels following the sham treatment (5.4 micrograms per milliliter). Whole-body hyperthermia treatment also significantly increased BDNF levels (28.3 picograms per liter) compared to baseline (25.9 picograms per liter).

    In healthy young adults, ten whole-body hyperthermia significantly increased irisin and BDNF levels. The authors noted that future studies should explore the effects of whole-body hyperthermia on adipose tissue, which also produces irisin.

  • Time-restricted eating involves restricting the timing of food intake to certain hours of the day (typically within an 8- to 12-hour time window) without an overt attempt to reduce caloric intake. Increasing the amount of time spent fasting each day has been used to treat metabolic diseases such as type 2 diabetes and high cholesterol, increase muscle mass, decrease fat mass, and improve exercise performance. Findings of a recent report demonstrate the beneficial effects of time-restricted eating on exercise performance in power athletes.

    Increasing muscle mass and decreasing fat mass is an important goal for many athletes because increasing their strength-to-mass ratio improves performance. While time-restricted eating is one strategy to improve body composition, previous research has shown that other types of intermittent fasting (e.g., religious fasting during Ramadan) decrease power output and endurance. Another study involving intermittent fasting with caloric restriction found similar deficits in athletic performance. The effects of long-term time-restricted eating without caloric restriction are unknown.

    The researchers recruited healthy young males who were currently practicing a power-sport at least three times per week and had been practicing for at least three years. Twelve participants (average age, 22 years) completed four weeks of time-restricted eating and four weeks of a standard meal pattern in random order with two weeks of wash-out in between. During the time-restricted eating period, participants consumed all of their food within an eight-hour window. The researchers measured body composition using X-ray and athletic performance using the Wingate test, a cycling challenge that measures power and total work.

    Time-restricted eating produced a significant increase in total work (a measure of force over a set distance) and average power output (a measure of work over time). These improvements translated to a one second reduction in sprinting time. The participants achieved this change after four weeks of time-restricted eating, but not after one week. Time-restricted eating did not improve peak power, endurance, or body composition.

    Time-restricted eating, along with regular training, improved exercise performance in athletes. Given that the difference between the current and former 400 meter running world records is only 15 hundredths of one second, the one second decrease in sprinting time produced by time-restricted eating is meaningful.

  • Aerobic exercise provides many health benefits, including a reduced risk of cardiovascular, metabolic, and other chronic diseases. Some of these benefits are due to adaptations in skeletal muscle that arise from the repair of cellular damage produced by the demand of exercise. One team of researchers aimed to determine the effects of antihistamines on muscle adaptation following acute and chronic high intensity interval training, often referred to as HIIT.

    Histamine is an organic molecule that acts as a neurotransmitter in the brain and spinal cord, while also regulating gut and immune function. Much of the research surrounding histamine is in relation to its effects in allergies and inflammation; however, recent research has demonstrated the role of histamine as a mediator of exercise-induced physiological responses. Histamine release is stimulated by exercise and promotes increased blood circulation, which may be important for facilitating muscle adaptation.

    The investigators conducted two phases of research including a randomized cross-over study of antihistamines and their effect in acute exercise and a double-blind, placebo-controlled, randomized study of chronic exercise training and antihistamine use. Participants in the acute exercise trial completed two exercise sessions on separate days. On one day, they took an antihistamine one hour prior to aerobic exercise and on the other day they took a placebo treatment. The researchers measured heart rate during exercise and blood pressure, heart rate, and arterial blood flow in the thigh before and after exercise.

    In the placebo group, blood flow in the thigh was increased by approximately threefold 15 minutes following exercise and remained 50 percent higher two hours following exercise. However, post-exercise blood flow was significantly reduced in participants who took an antihistamine (about 35 percent). Histamine treatment did not alter blood pressure or heart rate before or after exercise compared to the placebo group.

    For the study on chronic exercise, participants completed six weeks of high intensity interval training, which consisted of three weekly sessions of cycling. Half of the participants took an antihistamine one hour prior to exercise and the other half took a placebo. The researchers measured maximum exercise capacity by having participants exercise to exhaustion and measuring their oxygen output. They measured metabolic health by having participants complete an oral glucose tolerance test in which they consumed 75 grams of glucose (the amount of sugar in about two cans of non-diet soda) and had their blood glucose measured over two hours. They assessed vascular function by using ultrasound to measure the rate of blood flow in the thigh. Finally, the researchers took muscle biopsies from the thigh of participants in order to measure muscle adaptation.

    Over the six weeks of training, resting heart rate tended to decrease in the placebo group but not in the antihistamine group, indicating a blunting of exercise-induced adaptation. Peak power output during exercise also increased in both groups; however, this increase was significantly greater in the placebo group (12 percent increase) compared to the antihistamine group (7 percent increase). The time to exhaustion also improved significantly with training in the placebo group (81 percent increase) compared to the antihistamine group (31 percent increase). Training improved glucose tolerance significantly in the placebo group (26 percent increase), but this effect was blocked in the antihistamine group (1 percent increase). Finally, participants in the placebo group experienced a 37 percent improvement in vascular function while those in the antihistamine group experienced a 14 percent decrease in vascular function. Maximal blood flow during exercise also increased due to training in the placebo group only.

    In conclusion, antihistamine use blunted the functional adaptations in exercise capacity, whole-body glycemic control, and vascular function produced by exercise. Histamine activity is necessary for the integrative exercise training response in humans, potentially related to increases in blood flow.

  • Exercise puts a demand on skeletal muscle cells to produce energy at a faster rate than at rest. To do this, the body increases the delivery of fats to the muscle mitochondria while increasing the mitochondrial capacity to metabolize fats, a process called beta-oxidation. Researchers of a new study aimed to illuminate the cellular mechanisms of mitochondrial fat metabolism following moderate intensity aerobic exercise.

    Mitochondria are cellular structures responsible for the production of energy in the form of adenosine triphosphate (ATP). The inner membrane of mitochondria possess a series of enzymes called the electron transport chain. These enzymes transfer electrons from carbohydrates and fats (as well as proteins and nucleic acids to a lesser extent) to the final enzyme in the chain that produces ATP. Electron transfer flavoprotein is an enzyme in this chain that transfers electrons from fats, specifically. The authors of this report have previously presented data demonstrating an increase in electron transfer flavoprotein activity in mice after aerobic exercise training.

    The investigators recruited fifteen healthy sedentary adults (average age, 28 years) with a normal body mass index. Participants completed one hour of cycling at 65 percent of their maximum aerobic capacity on one day and rested the next day. The researchers collected biopsies from the participants' thigh muscle after they had rested and 15 minutes after they exercised. They analyzed the muscle mitochondria for the abundance of electron transfer flavoprotein activity and for the metabolism of fats and nonfat fuel sources.

    Following exercise training, mitochondrial metabolism of fats and non-fat sources increased, although this relationship was not statistically significant. Also noted was a six percent increase in hydrogen peroxide, which is a byproduct of fat metabolism that damages cells. Although fat metabolism increased, the authors reported no increase in electron transfer flavoprotein activity abundance.

    They authors concluded that just one session of moderate intensity aerobic exercise in sedentary adults increases energy metabolism of both fats and non-fat sources. They suggested future research would include a larger sample of participants.

  • The circadian rhythm is controlled by a central clock in the brain and by peripheral clocks in skeletal muscle, adipose tissue, and other organs. Together, these clocks coordinate the expression of genes related to a variety of metabolic processes with daily light, eating, and activity cycles. New research suggests that exercising in the afternoon maximizes metabolic benefits due to circadian-driven cycles.

    While light is the main driver of the central circadian clock in the brain, peripheral clocks are responsive to a number of environmental signals such as eating and exercise. When these activities are out of sync with normal light/dark cycles, as seen with shift work, metabolic dysfunction occurs. Previous research in humans has reported severely impaired glucose and insulin regulation with circadian disruption.

    The investigators recruited a group of 32 males (average age, 58 years) who had type 2 diabetes or were at risk for developing type 2 diabetes. Participants completed 12 weeks of combined aerobic and resistance training in the morning (8 a.m. to 10 a.m.) or afternoon (3 p.m. to 6 p.m.). The researchers measured insulin tolerance, body composition, and exercise performance before and after the intervention.

    Participants who exercised in the afternoon improved their insulin sensitivity by 34 percent, while insulin sensitivity in the morning group improved only 3 percent. The afternoon group also experienced a significantly greater reduction in fasting glucose levels, fat mass, percent body fat, and exercise performance. Although it wasn’t statistically significant, afternoon exercise also tended to improve glucose output from the liver, another marker of metabolic health.

    The authors concluded that exercising in the afternoon improved insulin tolerance, body composition, and exercise performance to a greater extent than morning exercise in those with metabolic dysfunction. The authors speculated that circadian cycles in skeletal muscle or cycles in body hormone levels may be the cause of this effect, although further research is needed to fully understand the impact of exercise timing on metabolism.

    Link to full study. Learn more about the importance of circadian rhythms in this episode featuring expert Satchin Panda.

  • Just one night of sleep deprivation can impair arterial function, and chronically poor sleep increases the risk of developing cardiovascular disease. Conversely, high intensity interval exercise can improve multiple markers of heart health. In this report, researchers tested the effects of exercise on flow mediated dilation, a measure of vascular function, in sleep-deprived participants.

    Flow mediated dilation is a measure of how wide an artery expands in response to increased blood flow. Meals high in fat normally cause dysfunction in blood vessels, impairing their ability to dilate. Previous research reports that high intensity exercise improves flow mediated dilation following a meal.

    Fifteen healthy active men (average age, 31 years) completed three nights of sleep for this study. The first night, participants slept a full eight hours and ate a high-fat test meal the next morning. The second night, participants slept a full eight hours, then performed high intensity interval training before eating. The third night, participants slept three and one half hours or less, then performed the same exercise and ate the same meal. The researchers measured flow mediated dilation at multiple time points.

    After comparing the post-meal flow mediated dilation following a full night of sleep and a full night of sleep plus exercise, the authors found that exercise improved arterial function. Impressively, the benefit of exercise remained following a night of sleep deprivation. Flow mediated dilation rates were similar between exercise conditions regardless of sleep duration the night before.

    The authors concluded that high intensity exercise improves artery function and that these benefits remain even after a night of sleep deprivation. However, they recommended that people get a full night of sleep before strenuous exercise to get the most benefit.

  • Exercise is a critical component of public health recommendations to prevent cancer. A growing body of scientific research demonstrates that engaging in exercise after a cancer diagnosis can improve outcomes, but the mechanisms that mediate these effects are not fully characterized. Findings from a new study demonstrate that exercise alters the metabolism of cytotoxic T cells to improve their ability to attack cancer cells.

    Cytotoxic T cells play key roles in the body’s immune response. They destroy malignant cells by triggering apoptosis – a type of cellular self-destruct mechanism that rids the body of damaged or aged cells.

    The authors of the study placed mice with cancer into one of two groups. Half of the mice exercised on a treadmill, but the other half remained inactive. They transferred cytotoxic T cells from the mice that exercised into the inactive mice. Then they isolated T cells, blood, and tissues from the exercising mice. Finally, the authors injected both groups of mice with antibodies that would destroy the animals' cytotoxic T cells.

    The mice that exercise exhibited slower cancer growth and reduced death rates than those that remained inactive. The inactive mice that received the cytotoxic T cells from exercised mice showed marked improvements in their disease status. The exercising mice had high blood levels of lactate, which altered the T cells' metabolism and increased the cells' activity. Destroying the animals' cytotoxic T cells negated the beneficial effects that the exercise had in terms of cancer growth and survival.

    Taken together, these findings suggest that exercise alters cytotoxic T cells to mediate exercise-induced cancer suppression. Treatment protocols that incorporate exercise might improve outcomes by activating the immune system.

  • People living with two or more chronic diseases – a condition known as multimorbidity – are more likely to take multiple medications, have more frequent and longer hospital stays, and die prematurely than those with only one chronic disease. Multimorbidity is common among older adults.60240-2/fulltext) Findings from a recent meta-analysis suggest that exercise benefits people with multimorbidity.

    Evidence indicates that exercise increases muscle strength, improves cardiovascular and metabolic health, and boosts mood by reducing visceral fat mass and activating a wide range of anti-inflammatory processes in the body. A key feature of many chronic diseases is inflammation, but exercise may disrupt inflammation to elicit its beneficial effects.

    The authors of the meta-analysis reviewed data from 23 randomized controlled studies that investigated the health effects of exercise in people with multimorbidity, defined as having two or more chronic health conditions (arthritis of the knee or hip, hypertension, type 2 diabetes, depression, heart failure, ischemic heart disease, or chronic obstructive pulmonary disease). The study participants were between the ages of 50 and 80 years. The average duration of the studies was 12 weeks and included a variety of exercise protocols, including aquatic exercise, strength training, aerobic training, and tai chi, performed two to three times per week.

    The analysis revealed that exercise therapy interventions improved physical fitness (determined by walking distance and speed) and decreased symptoms of anxiety and depression, especially among younger adults. The interventions didn’t increase knee, arm, or back pain, or falls and fatigue. Study participants who engaged in regular exercise were less likely to be hospitalized, develop pneumonia, or experience extreme fatigue.

    These findings suggest that exercise exerts beneficial effects on people with multimorbidity and serves as a viable option in managing their conditions.

  • Current public health guidelines recommend that adults engage in regular physical activity for optimal health. Findings from a new study suggest that a combination of both aerobic and strength activities reduces the risk of death from all causes as well as specific causes.

    According to the guidelines, adults should engage in at least 150 minutes of moderate-intensity aerobic physical activity or at least 75 minutes of vigorous-intensity aerobic physical activity each week, or an equivalent combination of both. They should also engage in muscle-strengthening activities of moderate or greater intensity on two days or more each week.

    The population-based cohort study, which involved nearly 480,000 adults, drew on data from the National Health Interview Survey, an ongoing, cross-sectional survey of people living in the United States. The study participants reported how much leisure time aerobic and strength physical activity they engaged in each week. Then the authors of the study categorized them as having insufficient activity, aerobic activity only, strength activity only, and both aerobic and strengthening activities, based on the guidelines.

    The authors found that the participants who engaged in recommended amounts of aerobic or muscle-strengthening activity had a lower risk of death from all causes, and these benefits were even greater if they engaged in both types of activities. They noted similar reductions in risk of death from cardiovascular disease, cancer, and chronic lower respiratory tract diseases.

    These findings suggest that adherence to public health guidelines for exercise reduce the risk of disease and death and provide support for interventions to improve compliance.

  • Exercise improves cognitive function and reduces the risk neurodegenerative diseases such as Alzheimer’s disease. Some of these benefits are mediated by brain-derived neurotrophic factor (BDNF). Findings from a 2012 study showed that regular exercise improved cognitive function and increased BDNF levels, but a genetic variant in BDNF influenced the degree of these effects.

    BDNF is a protein that acts on neurons in the central and peripheral nervous systems. A single-nucleotide polymorphism (SNP) in the gene that encodes BDNF causes a substitution of the amino acid valine (Val) by methionine (Met) in the BDNF protein. This genetic variant, known as Val66Met, alters exercise-driven release of BDNF and affects learning, memory, and emotion.

    The intervention study involved 75 sedentary, healthy, young adults between the ages of 18 and 35 years. The participants took memory tests and mental health surveys before and after engaging in their randomly assigned respective activities: no exercise; four weeks of exercise with exercise and a test on the last day; four weeks of exercise, without exercise on the final test day; or a single bout of exercise on the last test day.

    The participants who engaged in exercise showed improvements in memory and experienced lower levels of perceived stress, but only if they exercised for four weeks including the final day of testing. Participants who engaged in a single bout of exercise showed no changes in memory performance and demonstrated higher perceived stress levels. The authors of the study noted improvements in the participants' memory only if they did not carry the Val66Met variant, suggesting that the associated reduction in BDNF release attenuated some of the cognitive benefits of exercise. They also noted that the improvements in cognitive function were not correlated to improvements in mental health.

    These findings suggest that the variable effects of exercise on brain function are related to a genetic variant that influences the production of BDNF.

  • From the article:

    For these experiments, the researchers injected the BDNF gene or protein in a series of cell culture and animal models, including transgenic mouse models of Alzheimer’s disease; aged rats; rats with induced damage to the entorhinal cortex; aged rhesus monkeys, and monkeys with entorhinal cortex damage.

    In each case, when compared with control groups not treated with BDNF, the treated animals demonstrated significant improvement in the performance of a variety of learning and memory tests. Notably, the brains of the treated animals also exhibited restored BDNF gene expression, enhanced cell size, improved cell signaling, and activation of function in neurons that would otherwise have degenerated, compared to untreated animals. These benefits extended to the degenerating hippocampus where short-term memory is processed, one of the first regions of the brain to suffer damage in Alzheimer’s disease.

    […]

    “In this series of studies, we have shown that BDNF targets the cortical cells themselves, preventing their death, stimulating their function, and improving learning and memory. Thus, BDNF treatment can potentially provide long-lasting protection by slowing, or even stopping disease progression in the cortical regions that receive treatment.”

  • β-hydroxybutyrate production consequent to exercise induces within the muscle the activities of a key promoter involved in the production of brain-derived neurotrophic factor.

    From the article:

    Studies have shown that BDNF levels in the brains of people with Alzheimer’s or Huntington’s disease are, on average, half that of people without either brain-damaging disease.

    Among the key findings of the current study was that a ketone, a chemical naturally produced in the liver called beta-hydroxybutyrate (DBHB), triggers biological reactions that activate the BDNF gene to produce more of its protein. DBHB has long been known to build up in the body and brain with exercise. Ketones are “by-product” chemicals made when animals break down fat as an alternative energy source after having drained more readily available sugar stores during exercise.

    Specifically, Chao says, the researchers found that DBHB prevents other proteins in the brain known as histone deacetylase complexes, or HDACs, from suppressing BDNF production by altering the environment of the BDNF gene.

  • From the article:

    The team evaluated blood levels of BDNF before and after a three-month program of aerobic exercise in 15 overweight or obese men and women. The seven men and eight women, ages 26 to 51, worked out on a treadmill and bicycle. They were asked about their calorie intake and told to continue eating their usual number of calories. The participants were unaware that one of the study’s objectives was to evaluate changes in food intake.

    At the end of the study, the subjects had decreased BMI, waist circumference, and blood pressure, the data showed. They also reported consuming fewer calories than at the beginning of the study. Over the three months, BDNF levels greatly increased. This higher the concentration of BDNF, the less the subject’s intake of calories and the greater the weight loss, Araya said.

    Thus, it is possible that increases in BDNF suppress appetite, she said. They did not test appetite suppression directly, but some past studies have shown that aerobic exercise suppresses appetite.

  • Dementia, a form of cognitive decline that interferes with normal daily living, affects approximately 50 million people worldwide. Findings from a recent study suggest that regular physical exercise can reduce the risk of developing dementia.

    Dementia commonly occurs in older age and is characterized by a progressive loss of memory, executive function, and reasoning. Approximately 70 percent of all dementia cases are due to Alzheimer’s disease. Previous research has demonstrated that the incidence of dementia is influenced by non-modifiable risk factors, such as increasing age, ethnicity, and the presence of a genetic variant known as APOE4.

    Researchers are less certain about modifiable factors that may alter dementia risk, including health behaviors such as exercise. The current retrospective cohort study investigated which individuals developed dementia and the factors associated with its incidence.

    The study involved 206,073 people over the age of 50 years who were enrolled in the Health Check Ubon Ratchathani Project in Thailand. The authors of the study questioned participants about their medical and personal history, including the use of medications and exercise habits. Six years later, investigators reviewed the participants' electronic medical records for the incidence of physician‐diagnosed dementia. They found that a lack of physical exercise was associated with an increased risk of developing dementia in a dose-dependent manner. Exercising three to five days per week reduced the risk of dementia by 37 percent as compared to no physical exercise, while exercising more than five days per week reduced dementia risk by 59 percent.

    These findings suggest that physical exercise at least three days a week can reduce the risk of developing dementia. Further clinical trials with longer follow-ups are needed to confirm the impact of lifestyle factors on dementia risk.

  • Breast cancer is one of the leading causes of death among women living in the United States, claiming the lives of approximately 41,000 women each year. Findings from a new study suggest that regular physical activity can reduce the risk of developing breast cancer.

    The Physical Activity Guidelines for Americans recommend that adults engage in at least 150 to 300 minutes of moderate-intensity, or 75 to 150 minutes of vigorous-intensity aerobic physical activity each week. Moderate-intensity exercises include brisk walking, light cycling, or playing doubles tennis. Vigorous-intensity exercises include jogging, hiking, rigorous cycling, or playing basketball, soccer, or singles tennis. Data indicate that fewer than 23 percent of Americans achieve recommended levels of activity.

    The questionnaire-based study assessed the lifestyles of 1,340 women with breast cancer at multiple times throughout survivorship, including before, during, and after treatment. Women who met the guidelines before and after treatment were 55 percent less likely to have their cancer return and were 68 percent less likely to die from their cancer. But even if a woman didn’t start exercising until after her treatment began, she was likely to experience benefits, with a 46 percent lower risk of her cancer returning and a 43 percent lower risk of dying. These findings underscore the importance of engaging in regular activity as a means to reduce the risk of cancer recurrence and death and suggest that a breast cancer diagnosis can provide an impetus to begin exercising.

  • Cardiorespiratory fitness is a measure of the body’s aerobic capacity – the ability to deliver oxygen to skeletal muscles – during sustained physical activity. Poor cardiorespiratory fitness, along with dyslipidemia, family history, hypertension, age, cigarette smoking, diabetes mellitus, obesity, and physical inactivity, increases a person’s risk for cardiovascular disease and death. Findings from a new study indicate that cardiorespiratory fitness measured by submaximal testing predicts risk for deaths from all causes.

    The most accurate way to assess cardiorespiratory fitness involves measuring maximal oxygen uptake, often referred to as VO2 max, during a graded exercise test in a laboratory, clinical, or research setting. The sheer logistics of measuring VO2 max in large groups of people present challenges, however. Submaximal exercise testing, which typically involves completion of a standardized exercise or task using a treadmill or bicycle, is a viable option in these settings.

    The study involved more than 58,000 people between the ages of 40 and 69 years who were enrolled in the UK Biobank Prospective Study. The authors of the study categorized the participants according to their level of risk based on the participants' age, sex, medical history, and biochemical indicators. Then the participants underwent submaximal exercise testing using a stationary exercise bicycle.

    The results of the submaximal exercise testing revealed a linear relationship between cardiorespiratory fitness and the risk of death. In fact, submaximal exercise testing served as a highly reliable predictor of death, even beyond conventional risk factors, especially among people with few risk factors.

  • Exercise-induced bronchoconstriction – a narrowing of the airways in response to exercise – occurs in as much as 10 percent of the general population and up to 50 percent in some fields of competitive athletics. Findings from a meta-analysis suggest that vitamin C might reduce the incidence of exercise-induced bronchoconstriction.

    Previous research demonstrated that vitamin C can triple respiratory tissue levels within an hour or two of a single oral dose of 1 or 2 grams. This local increase in vitamin C concentration appears to protect against acute increases in airway oxidative stress. In addition, vitamin C inhibits the production of prostaglandins and leukotrienes, biological compounds that participate in the pathogenesis of exercise-induced bronchoconstriction.

    In addition, vitamin C halved the incidence of the common cold among people experiencing heavy short-term physical stress – an indication that vitamin C might also have other effects on people experiencing heavy physical exertion.

    The authors of the current conducted analyses of nine studies that investigated varied aspects of the effects of vitamin C on exercise-induced bronchoconstriction. Three placebo-controlled studies analyzed the relative exercise-induced decline in forced expiratory volume, or FEV1, (a measure of respiratory capacity) with or without a vitamin C. They found that doses ranging between 0.5 and 2 grams of vitamin C reduced FEV1 decline by half. Similarly, five studies investigated the effects of vitamin C supplementation on respiratory symptoms after short-term heavy physical work and found that incidence was halved. One study investigated the duration of respiratory symptoms in young male swimmers and also found that incidence was halved.

    The authors noted that a variety of factors might influence whether and to what degree vitamin C affects respiratory function during exercise, including the type of activity and the conditions under which it is performed, among others.

  • Public health officials and healthcare providers commonly recommend exercise as a strategy to prevent or manage the symptoms of type 2 diabetes, but the cardiometabolic response to exercise is variable. Whereas exercise improves insulin sensitivity and promotes cardiovascular health in most adults (responders), exercise exerts a paradoxical effect in which metabolic health is compromised in as many as 69 percent of adults (non-responders). Findings from a recent study suggest the variable effects of exercise in people with prediabetes may be due to alterations in gut microbial fermentation.

    Microbial fermentation is the process by which gut bacteria break down and utilize carbohydrates in the gut. The metabolites produced during microbial fermentation include short-chain fatty acids and branched-chain amino acids, which are absorbed and used by the host. Short-chain fatty acids improve symptoms of diabetes, but branched-chain amino acids have the converse effect

    The study involved both humans and mice. The human study included 39 overweight or obese men with prediabetes who were between the ages of 20 and 60 years. Participants were randomized to engage in either sedentary activities or supervised exercise training for 12 weeks. They maintained their usual diet throughout the study period. At the end of the 12-week period, fecal microbial samples from two of the participants (responders and non-responders) were transplanted into obese mice.

    The results demonstrated that the responders' microbiota displayed increased production of short-chain fatty acids, whereas those of the non-responders displayed increased production of brain-chain amino acids. Fecal microbial transplantation from responders mimicked the effects of exercise on alleviation of insulin resistance in the mice, but fecal transplants from the non-responders did not. These findings may augment and facilitate clinical management of symptoms of diabetes.