Effects of transcranial direct current stimulation (tDCS) on isometric endurance performance and electromyographic activity of the vastus lateralis in healthy male.

To investigate the effects of anodal tDCS on isometric endurance peformance and sEMG activity of the vastus lateralis in healthy male with experience in resistance training. Fifteen healthy, resistance-trained males aged 18 to 35 participated in three sessions, each separated by one week. The initial session included an maximal isometric voluntary contraction (MIVC) test and familiarization with the fatigue task. In the second and third sessions, conducted randomly, participants underwent either anodal tDCS or placebo tDCS (sham). Immediately after the conditions, the subjects performed the fatigue task for right knee in the horizontal leg-press exercise, consisting of eight, lasting five seconds and having a five-second interval between contractions. The results showed no interaction between conditions and contractions in isometric endurance performance across contractions (p = 0.78) or in the sEMG activity of the vastus lateralis muscle (p = 0.94). The specific anodal tDCS protocol used in this study does not enhance isometric strength endurance or surface electromyographic activity of the vastus lateralis muscle in strength-trained men.