A study io mice showed why taking NSAIDS (Non-Steroidal Anti-Inflammatory Drugs), to reduce muscle pain before, during or after exercise, can reduce the gains in endurance from aerobic training (PNAS, June 27, 2017;114(26):6675–6684). The processes that heal damaged tissue in your body use the same immune cells and chemicals that fight infections. Certain prostaglandins that heal damaged tissues are the same prostaglandins that cause muscle soreness. These prostaglandins can hasten healing of muscles damaged by vigorous exercise by increasing production of stem cells to replace damaged muscle cells. They also increase endurance by increasing blood flow to damaged muscles, widening blood vessels and increasing the ratio of blood capillaries to muscle fibers. Taking NSAIDs hinders this process and can prevent the gains in endurance that you would expect to get from your exercise. Earlier studies in humans showed that taking NSAIDs can reduce the gains in endurance from aerobic exercise by restricting the ratio of blood capillaries to muscle fibers and decreasing the number of strength fibers in muscles (J Physiol Pharmacol, Oct 2010;61(5):559-63).
How NSAIDs Can Reduce Benefits of Strength Training
I recently reported on a study showing that taking NSAIDs before or after lifting weights can delay recovery and reduce the beneficial effects of lifting weights to strengthen muscles and bones (Med & Sci in Sports & Ex, April 2017;49(4):633–640) . To make a muscle stronger and to increase its endurance, you have to exercise it long enough and hard enough to damage the muscle fibers. Then when the muscle fibers heal, the muscles become larger and stronger. Bones also need resistance force on them to make them stronger (Nutr Res Pract, 2010;4(4):259–69), and anything that makes muscles stronger should also make the corresponding bones larger and stronger. To make muscles and bones stronger, you take an intense workout that makes your muscles feel the burn during the workout and the next day your muscles feel sore because of the fiber damage you have caused. If you take NSAIDs such as ibuprofen to reduce the muscle soreness, you are also likely to reduce your gains in muscle and bone strength (Bone Rep, 2015;1:1–8; 2016;5:96–103).
• If you want to become significantly stronger and have greater endurance, you need to exercise intensely enough to feel a burn in your muscles during exercise. You can gain the benefits from your exercise and help to prevent injuries if you slow down or stop to take yourself out of the burn as soon as you start to feel it. When you have recovered your breath and the muscle burning is gone, you can pick up the pace again. Competitive athletes usually train by alternating going in and out of the burn during a single workout.
• You may be able to reduce after-exercise muscle soreness by taking NSAIDs before, during or after exercise, but they can reduce your gains in strength and endurance. Also be aware of their other possible side effects such as increased risk for kidney damage (Emergency Medical Journal, July 5, 2017) and gastro-intestinal bleeding.
• Applying ice to sore muscles will reduce the soreness as it helps to reduce pain, but cooling also can delay healing. See Why Ice Delays Recovery