Analgesics and Exercise Performance in Pain-Free Situations: A Systematic Review and Meta-Analysis.

Abstract Analgesics have been largely consumed as ergogenic in sports settings in pain-free situations. We summarized the collective evidence on their effects on exercise performance and exercise-induced pain through a systematic review and meta-analysis. The risk of bias and certainty of evidence of randomized placebo-controlled crossover studies were assessed using the Cochrane Risk of Bias 2 tool and the Grading of Recommendations Assessment, Development and Evaluation approach. A multilevel random-effects model compared the standardized mean difference among studies. Twenty-three studies investigating the effects of aspirin ( n =4), ibuprofen ( n =6), celecoxib ( n =1), flurbiprofen ( n =1), paracetamol ( n =16) and tramadol ( n =4) on exercise performance in pain-free situations showed a low risk of bias and moderate certainty of evidence. The very small effect of analgesics in grouped data (standardized mean difference=0.14; p =0.003) or data separated by exercise modalities (standardized mean difference=0.18; p =0.04) was unlikely to produce ergogenic benefits. Subgroup analysis evidenced that tramadol enhanced exercise performance in cycling exercises (standardized mean difference=0.38; p =0.03). No beneficial effect was observed in pain (standardized mean difference=-0.22; p =0.61). Analgesics commonly used in pain-free situations are unlikely to enhance exercise performance. Beneficial effects of tramadol on performance require confirmation in real-world contexts and different exercise modes.