Photobiomodulation (PBM) therapy at 904 nm mitigates effects of exercise-induced skeletal muscle fatigue in young women.
Muscle fatigue is a process influenced by several mechanisms such as concentration of metabolic substrates, changes in blood flow, and increases in reactive oxygen species that impair contractile muscle function. In this context, photobiomodulation has been investigated for preventing muscle fatigue, with reports of positive effects on muscle performance. This study aimed to investigate the effects of 904-nm LASER photobiomodulation on rectus femoris muscle performance in young women. Eighteen young women participated in a randomized, participant and assessor-blinded crossover trial with placebo control. Active LASER (904 nm, 60 mW, 250 Hz, 3.6 J per diode, total dose of 129.6 J) intervention was applied prior to an isokinetic fatigue protocol consisting of a set of 60 concentric quadricep contractions at a constant dynamometer angular velocity of 180°/s. Compared to placebo, LASER photobiomodulation significantly reduced muscle fatigue across a range of indicators including reduced ratings of perceived exertion (P = 0.0139), and increased electromyographic fatigue index (EFI) (P = 0.005). The isokinetic dynamometer performance analysis demonstrated that LASER photobiomodulation increased peak torque (P = 0.04), time to peak torque (P = 0.042), total work (P = 0.032), average power (P = 0.0007), and average peak torque (P = 0.019) between both experimental conditions. No significant difference was observed for work fatigue index (P = 0.29) or for lactate concentration (P > 0.05). Photobiomodulation at 904 nm was effective in reducing fatigue levels and increasing muscle performance in young active women but had no effect on lactate levels.
['Toma|Renata Luri|RL|', 'Oliveira|Murilo Xavier|MX|', 'Renno|Ana Cláudia Muniz|ACM|', 'Laakso|E-Liisa|EL|http://orcid.org/0000-0003-4820-1090']
D000328:Adult D018592:Cross-Over Studies D004311:Double-Blind Method D004576:Electromyography D015444:Exercise D005260:Female D006801:Humans D019344:Lactic Acid D028022:Low-Level Light Therapy D008297:Male D009119:Muscle Contraction D018763:Muscle Fatigue D053581:Muscle Strength Dynamometer D018482:Muscle, Skeletal D019415:Torque D055815:Young Adult
Muscle fatigue Muscle performance Laser Lactate Electromyography Photobiomodulation therapy