PHOTOBIOMODULATION THERAPY ON PHYSIOLOGICAL AND PERFORMANCE PARAMETERS DURING RUNNING TESTS: DOSE-RESPONSE EFFECTS

This study was aimed at verifying effects of photobiomodulation therapy (PBMT) with different energy doses (15, 30, and 60 J per site) on physiological and performance parameters during running tests. Fifteen male recreational runners participated in a crossover, randomized, double-blind, and placebo-controlled trial. They performed testing protocol in 5 sessions with different treatments: control, placebo, and PBMT with 15, 30, or 60 J per site (14 sites in each lower limb). Physiological and performance variables were assessed during submaximal (at 8 and 9 km.h(-1)) and maximal running tests. Photobiomodulation therapy with 30 J significantly improved running economy (RE) at 8 and 9 km.h(-1) (3.01%, p=0.008 and 3.03%, p=0.009, respectively), rate of perceived exertion (RPE) at 8 km/h(-1) (7.86%, p=0.033), velocity at (V) over doto(2)max (3.07%, p=0.029), peak of velocity (PV) (1.49%, p=0.035), and total time to exhaustion (TTE) (3.41%, p=0.036) compared with placebo. Photobiomodulation therapy with 15 J improved running economy at 9 km/h(-1) (2.98%, p=0.025), rate of perceived exertion at 8 km/h(-1) (4.80%, p=0.010), PV (1.33%, p=0.008), total time to exhaustion (3.06%, p=0.008), and total distance (4.01%, p=0.011) compared with the placebo; whereas PBMT with 60 J only increased RE at 9 km/h(-1) (3.87%, p=0.024) compared with placebo. All PBMT doses positively affected physiological and/or performance parameters; however, magnitude-based inference reported that PBMT applied with 30 J led to more beneficial effects than 15 and 60 J.