The effects of phototherapy has been widely studied by some research groups. The investigators know that there are positive results with light application to improve muscle performance and delay fatigue. However, there are few studies showing its´ effects on muscular training. Therefore, the aim of this study was to assess the effects of phototherapy applied at different times during 12 weeks of strength training. For such, 48 volunteers, healthy male, from 18 to 35 years old were recruited to perform a strength training protocol for the anterior muscle of the thigh development. Volunteers performed the training protocol three times a week for 12 weeks. There were assessed isometric peak torque in isokinetic dynamometer, concentric peak torque, 1-repetition maximum test in the leg extension and leg press machines and bilateral thigh perimetry.