Effect of Whole-body Photobiomodulation on Muscular Performance Enhancement.

The adopted protocol of muscle damage will follow the recommendations from American College of Sports Medicine (ACSM) in 2009 for trained individuals. It consists of 8-12 repetitions above 70% of 1 Repetition Maximum (1RM) with 1 minute of rest between sets and 2 minutes between exercises. The protocol will be composed as follows: 3 sets of 10 repetitions for each exercise, with an emphasis on producing microlesions in the muscle tissue (muscle damage protocol).

PBMT will be administered using the Joovv Elite System, which has 6 panels of red LEDs (660±10nm) and 74 panels of infrared LEDs (850±10nm), totaling 900 LEDs covering an area of 12,193 cm². Athletes will stand 20 cm in front of the device, wearing only swim shorts to expose their thigh muscles and other body areas to the light. The total irradiation time will be 20 minutes, with 10 minutes (600 seconds) of irradiation for the anterior region and another 10 minutes (600 seconds) for the posterior region. The active PBMT dose applied in each region (anterior or posterior) will be 48.97 J/cm², with an irradiance of 81.62 milliwatt (mW)/cm². The PBMT Sham dose applied in each region (anterior or posterior) will be 0 J/cm², with an irradiance of 0 mW/cm².