Multiple studies have found that taking NSAIDs such as ibuprofen may reduce muscles’ ability to recover after exercise, blunt adaptations in muscle stem cells, and put excessive stress on the kidneys in people that vigorously exercise.

One mechanism by which NSAIDs blunt some of the positive effects in muscle is through the inhibition of inflammatory mediators such as prostaglandins. While it is good to generally keep inflammation at bay, part of the mechanism by which exercise exerts beneficial effects is by acutely generating inflammation which induces a hormetic response and activates many anti-inflammatory pathways that often stay active for a long period after the exercise resulting in a net positive anti-inflammatory response. Activation of the body’s anti-inflammatory pathways is much more powerful than supplemental anti-inflammatory drugs.

Additionally, prostaglandins are important for vasodilation to increase blood flow to multiple tissues. NSAIDs decrease vasodilation which is one way they can increase the risk of stroke with long-term use.