The commonly used pain relievers acetaminophen and ibuprofen may impair musculoskeletal adaptations to progressive resistance exercise training by inhibiting exercise-induced muscle protein synthesis.
To test the hypothesis that acetaminophen and ibuprofen would diminish training-induced increases in fat-free mass, untrained men (n=26) aged ≥ 50 years participated in 16 weeks of high-intensity progressive resistance exercise training and bone-loading exercises and were randomly assigned to take ACET (1000 mg), ibuprofen (400 mg) or placebo 2 hours before each exercise session.
The primary outcome was the change in total body fat-free mass measured by dual-energy X-ray absorptiometry (DXA) at baseline and week 16. Our primary interest was in the comparison of the acetaminophen and placebo groups.