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.