Effect of transcranial direct current stimulation on sports performance for two profiles of athletes (power and endurance) (COMPETE): a protocol for a randomised controlled trial.

Abstract
Background Transcranial direct current stimulation (tDCS) is promising for improving motor and cognitive performance. Nevertheless, its mechanisms of action are unclear and need to be better characterised according to the stimulated brain area and the type of exercise performed. Methods/design This is a double-blind cross-over study, organised into two parts: the first is to assess the effects of tDCS on explosive performance (jump task) and the second is to assess the effects on endurance performance (cycling time trial task). Participants, who are recreationally active or athletes (cyclists, parkour practitioners), will receive two active tDCS sessions (over the left dorsolateral prefrontal cortex and right motor cortex) and one sham tDCS session (part A) or two daily tDCS sessions (one active sequence and one sham) over five days (part B). Motor and cognitive performance will be compared before and after the tDCS sessions (part A) and before and after the first session, after the last session and at day 12 and day 30 of each tDCS sequence (part B). Discussion This study investigates the acute and long-term effects of tDCS on the motor and cognitive performance in healthy subjects. It will try to evaluate if tDCS could be considered as a neuroenhancement technology according to the physical task investigated (endurance versus explosive).