Resistance exercise causes exercise-induced muscle injury (EIMI), triggering an acute local inflammatory response associated with delayed-onset muscle soreness (DOMS). DOMS is characterized by a predictable discomfort and decreased level of muscle performance and is believed to be the product of both mechanical and inflammatory processes. From the latter perspective, non-steroidal anti-inflammatory drugs (NSAIDs) have been investigated for their potential to alleviate DOMS-associated symptoms. Such analgesics exert their effects by blocking the formation of prostaglandins; however, prostaglandins, specifically prostaglandin F 2?, also play an important role in skeletal muscle regeneration. While some have advocated the use of NSAIDs for the relief of EAP, research demonstrating the necessity of inflammation for adaptation and regeneration suggests their use may be counter-productive for those striving toward muscular fitness goals. In this double-blind design, twenty-three recreationally-trained college-aged males were randomly assigned to placebo or naproxen sodium treatment groups. Treatments were prophylactically administered twice per week, in conjunction with a supervised periodized upper body resistance training program. Main effects for time and exercise were seen for repeated acute systemic plasma PGF2? metabolite concentrations, acute arm circumference response to exercise, strength, dominant arm lean and fat tissue, and non-dominant arm bone mineral content. No significant treatment effects were detected for any dependent variables, thus twice weekly naproxen sodium (440mg) does not appear to inhibit skeletal muscle adaptation to resistance exercise in recreationally-trained college-aged males over a 6-week time period
