Prescription strength ibuprofen interferes with prophylactic adaptations to heavy exercise

Purpose: This proof of concept study was designed to assess the influence of prescription-strength Ibuprofen (IBU) on the repeated bout effect (RBE) of heavy exercise. METHODS: Eight males (23 ± 4 yrs) with no recent history of lower-body resistance training completed two separate testing phases separated by a seven-day washout period. Each phase consisted of two sessions of single-legged resistance exercise (RE), performed on the same leg, separated by ten days. One RE trial included 10 sets of 10 repetitions of maximal unilateral eccentric leg extensions at 120% 1RM. Each phase was characterized by a distinct treatment of either 800mg IBU or placebo (PLA), which subjects consumed 45 minutes prior to RE and in 8h increments for 72h. A randomly counterbalanced, crossover design was utilized so each subject received both treatments. Muscle recovery variables (soreness, muscle function, plasma creatine kinase) were measured 24 and 72 hours following each RE session. Magnitude-based inferences were used to evaluate all outcomes. RESULTS: The increase in ascending and descending muscle soreness 24h after the second session of RE (RE2) was ‘likely’ less with PLA compared to IBU. Specifically, the reduction in ascending muscle soreness with PLA (RE1: 43mm to RE2: 27mm) was absent with IBU (RE1: 39mm to RE2: 39mm). A similar response was observed for descending muscle soreness. Furthermore, the impairment in total work performed 72h after RE2 was ‘likely’ attenuated with PLA (RE1: 598J to RE2: 13.1J), but not IBU (RE1: 335.1J to RE2: 343J). Decreases in work performed in the first five reps followed a similar pattern. Finally, the impact of IBU on all muscle strength and CK measurements were ‘unclear’. CONCLUSIONS: In general, IBU consumption appeared to interfere with the RBE, compared to PLA. Follow-up work is needed to confirm these findings but these preliminary data suggest that prescription-strength dosing of IBU following skeletal muscle trauma may need to be reconsidered