Effect of photobiomodulation on maximal lactate production rate on swimmers: a randomized, crossover, double-blind and placebo-controlled study

Abstract

This study aimed to verify the acute effect of photobiomodulation (PBM) on maximal lactate production rate (VLamax) in front crawl swimmers. Methods: Fifteen male swimmers (20.9 ± 2.4-year-old) participated in this study. Three sets of front crawls were performed at distances of 100-, 200- and 400-m under three experimental conditions: PBM (420 J), placebo (PLA) and control (C) in this randomized, crossover, double-blind and placebo-controlled study. PBM or PLA were applied or simulated before performance tests. One-way Anova for repeated measurements were used for statistical analyses. Results: The results showed that the prior PBM application did not affect VLamax in front crawl swimmers: VLamax 100-m (PBM = 0.20 ± 0.05 mmol·L-1·s-1; PLA = 0.20 ± 0.04 mmol·L-1·s-1 and C = 0.21 ± 0.04; mmol·L-1·s-1); 200-m (PBM = 0.09 ± 0.03 mmol·L-1·s-1; PLA = 0.08 ± 0.02 mmol·L-1·s-1 and C = 0.08 ± 0.02 mmol·L-1·s-1) and 400-m (PBM = 0.04 ± 0.01 mmol·L-1·s-1; PLA = 0.04 ± 0.01 mmol·L-1·s-1 and C = 0.03 ± 0.01 mmol·L-1·s-1). Nor effect swim time (ST) performance: ST 100 m (PBM = 65.5 ± 6.3 s; PLA = 65.2 ± 5.6 s; C = 66.0 ± 5.9 s); ST 200 m (PBM = 148.5 ± 17.9 s; PLA = 149.4 ± 16.4 s; C = 150.1 ± 17.9 s); ST 400 m (PBM = 327.7 ± 38.2 s; PLA = 321.6 ± 47.7 s; C = 329.5 ± 41.2 s). Conclusions: PBM application prior front crawl swimming tests did not significantly modify the VLamax on swimmers covering distances of 100-, 200- and 400-m.