Acute Effect of Transcranial Direct Current Stimulation on Power During Flywheel Squatting: a Randomized, Placebo-controlled, Crossover Clinical Trial

Transcranial direct current stimulation (tDCS) has been investigated as an ergogenic strategy; however, its acute effects on muscle power-especially when combined with flywheel resistance training (FRT)-have not yet been explored. The aim of this study is to investigate the acute effects of anodal, cathodal, and sham tDCS on muscle power and neuromuscular variables during flywheel squat exercise. This is a randomized, double-blind, placebo-controlled, crossover clinical trial; 22 physically active men aged 18 to 35 years with strength training experience will be recruited. Volunteers will complete a minimum of three familiarization sessions and three experimental sessions, during which they will undergo anodal, cathodal, or sham tDCS conditions (2 mA, 20 min) in random order, with a minimum 48-hour interval between sessions. Following each stimulation, they will perform four sets of 1+8 repetitions of the flywheel squat. Concentric and eccentric power, the eccentric/concentric ratio, electromyographic activation (RMS, median and peak frequency), and subjective ratings of perceived exertion and discomfort will be analyzed. A repeated-measures ANOVA (3 conditions × 4 sets × 3 periods) will be performed, with Bonferroni post-hoc testing and a significance level of p < 0.05 for all analyses.