Low Level Laser Therapy in Muscle Fatigue and Muscle Recovery

To achieve the proposed objectives it was performed a randomized, double-blinded, placebo-controlled trial, with voluntary participation of high-level soccer athletes. Participants received an application of low level laser prior to execution of a strenuous exercise. It was used a laser with a cluster of 5 diodes (810 nm, 200 mW each diode) with different doses (placebo, 2J, 6J, 10J) and power of 200mW. In a second step, with the optimal dose already defined, this was used to be applied with different powers in two experimental groups, 100mW and 400mW. The investigators analysed parameters related to volunteers exercise performance (torque peak / maximum voluntary contraction), delayed onset muscle soreness, and biochemical markers of muscle damage (CK and LDH), inflammation (interleukin 1 and 6, alpha tumoral necrosis factor) and oxidative stress (TBARS, CAT, SOD and carbonylated proteins). The analysis was performed before exercise protocols, after 1 minute, and 1, 24, 48, 72 and 96 hours after the end of exercise protocol in both parts of the study.