A Meta-Analysis of Randomized Controlled Trials on the Effects of Photobiomodulation Therapy on Running Performance.

OBJECTIVE: To conduct a meta-analysis to investigate the effects of Photobiomodulation (PBM) therapy on running performance.

INTRODUCTION: PBM has recently been advocated as a valuable non-pharmacological ergogenic strategy, however, the efficacy of PBM on running performance remains unproven.

METHODS: A computerized literature search was conducted until June 2023. The databases searched were PubMed/Medline, Embase, Scopus, SPORTDiscus, and Web of Science. Inclusion/exclusion criteria were determined through the PICO process. The running variables analyzed were time-trial or time-to-exhaustion. Results were combined with the standardized mean differences (SMD) and the 95% confidence intervals.

RESULTS: Twelve studies fulfilled the inclusion criteria. No significant effects in favor of PBM were found (SMD = 0.13; p = 0.11). There was no effect considering the presence (SMD = 0.16; p = 0.38) and absence (SMD = 0.11; p = 0.25) of training, and there was no dose-response effect ( p = 0.82).

CONCLUSION: Our findings indicate that PBM alone or combined with a training program does not improve running performance in terms of time-trial and time-to-exhaustion testing. More studies involving PBM plus training and doses higher than 1000 J are needed to determine if PBM is effective in improving running performance.