To examine the efficacy of naproxen sodium for exercise-induced dysfunction, muscle injury, and soreness.Design
Eight young adult, healthy males.Interventions
Ten sets of seven to 10 eccentric actions with each quadriceps femoris with a load equal to 85% of the eccentric one repetition maximum (IRM) followed by 10 days of naproxen sodium or placebo.Main Outcome Measures
Concentric IRM; cross-sectional area (CSA) and spin-spin relaxation time (T2) of quadriceps femoris, and subjective rating of thigh soreness pre- and 1,4, and 10 days postexercise; subjective rating of ability to sleep or perform morning activities daily during recovery.Results
Concentric IRM was reduced by (p = 0.0001) 41% day 1 of recovery; by day 4 of recovery, it had increased (p = 0.0145) to 24% below baseline in the drug trial, but did not change for the placebo trial. By day 10 of recovery, concentric IRM was 16 and 26% below (p = 0.0001) baseline for the drug and placebo trials, respectively. Quadriceps femoris CSA and T2 were increased (p ≤ 0.0250) after exercise, with the greatest (p = 0.0008) responses evident on day 4 of recovery. At this time, each variable showed greater increases (p ≤ 0.0129) for the placebo than for the drug trial 8 vs. 5 and 26 vs. 15%, respectively). The CSA of the quadriceps femoris showing an elevated T2 was 27 and 37% greater (p ≤ 0.0085) for the placebo than for the drug trial. on days 1 and 4 of recovery, respectively. The percentage of quadriceps femoris CSA with an elevated T2 (40%) was 1/3 greater (p ≤ 0.0138) for the placebo than for the drug trial on these days. Thigh soreness was lower (day 4, p = 0.0087) and the ability to sleep or perform morning activities was less (p ≤ 0.0030) compromised (days 3 and 4) during recovery in the drug trial.Conclusions
The results suggest that naproxen sodium improved recovery after eccentrically biased exercise, probably by attenuating expression of the inflammatory response to muscle injury.