Exercising against resistance strengthens muscles and bones, but taking non-steroidal pain medicines such as ibuprofen after lifting weights may prevent bones from becoming stronger (Medicine & Science in Sports & Exercise, April 2017;49(4):633–640). Aging weakens bones to increase risk for osteoporosis and bone fractures. The most effective way to strengthen bones and prevent this increased risk of bone fractures is to exercise against progressive resistance (Med Sci Sports Exerc, 2009:1510–30).
However, resistance training causes muscles to feel sore on the next day and many people take non-steroidal anti-inflammatory drugs (NSAIDs) after workouts to help relieve this soreness. This recent study shows that taking ibuprofen after workouts may weaken bones, rather than strengthen them.
Resistance Exercise Strengthens Muscles and Bones
To make a muscle stronger, you have to exercise it against resistance strong enough to damage the muscle fiber. Then when muscle fibers heal, muscles becomes larger and stronger.
Bones, as well as muscles, need resistance on them to become stronger (Nutr Res Pract, 2010;4(4):259–69). Anything that enlarges and makes muscles stronger also should help to 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. However, if you take a non-steroidal-anti-inflammatory drug such as Ibuprofen to reduce the muscle soreness, you may reduce the gain in muscle and bone strength.
The Study
Ninety post-menopausal women were randomly assigned for nine months to a three-days-a-week program of either:
- supervised resistance training, or
- a placebo-exercise group who did only stretching.
After each day of their exercise program, both groups were given either 400 mg of Ibuprofen or placebo pills. Those given Ibuprofen immediately after finishing each workout lost bone strength and density.
Previous studies showed conflicting results. One study found Ibuprofen taken after lifting weights prevented the expected growth and strengthening of both bones and muscles (Bone Rep, 2015;1:1–8; Bone Reports, 2016;5:96–103), while another study showed increased bone density in people taking Ibuprofen and lifting weights (J Bone Miner Res, 2010;25(6):1415–22).
How NSAIDs May Prevent Bones from Being Strengthened by Lifting Weights
The process of healing damaged tissue in your body is started by exactly the same immune cells and chemicals that fight infections. The chemicals that your body produces to heal damaged tissue and strengthen them are the same ones that also can cause muscle soreness. Many people take Ibuprofen or other NSAIDs immediately after workouts in the hope of decreasing this next-day muscle soreness, but the Ibuprofen can prevent bone strengthening by blocking the same chemicals that heal damaged tissue.
My Recommendations
If you lift weights to strengthen your bones and muscles, take Ibuprofen after workouts only if you need it to relieve some of the muscle soreness that follows workouts. Realize that the NSAID may also prevent some of the muscle and bone gains in strength and size that you are working to achieve.
Gabe Mirkin, M.D., is a sports medicine doctor and fitness guru. A practicing physician for more than 50 years and a radio talk show host for 25 years, Dr. Mirkin has run more than 40 marathons and is now a serious tandem bike rider with his wife, Diana. His website is http://drmirkin.com/. Click to read Gabe’s full bio.
Generalizing a study of 90 post-menopausal women to male athletes is too much of a stretch here, especially in light of the other conflicting studies cited on the effects of ibuprofen on muscle strength. The concluding recommendation seems reasonable, though, simply from a common-sense perspective.