The effect of transcranial direct current stimulation on dynamic balance after an endurance exhausting activity in mental fatigue condition

Anodal transcranial direct current stimulation (a-tDCS) is a new neuro-modulatory technique. This study aimed to investigate the effect of a-tDCS on dynamic balance after exhaustion. Fifteen endurance-trained men voluntarily attended five separate sessions. In the first session, Maximal aerobic speed (MAS) was measured. Then, the participants were randomly assigned to four different conditions: 1. Mental fatigue (MF)+a-tDCS, 2. MF+sham (s-tDCS), 3. a-tDCS, and 4. s-tDCS. In each session, after dynamic balance measurement, the participants were exposed to the conditions and received 20 min of anodal tDCS over the dorsolateral prefrontal cortex (DLPFC). Then, the participants performed a submaximal endurance activity at 70% of MAS until exhaustion. Immediately after exhaustion, dynamic balance was measured again. After exhaustion, the dynamic balance of the right leg under the a-tDCS condition was significantly higher than the MF+s-tDCS (P= 0.008). The dynamic balance significantly decreased from pre- to post-test in MF+s-tDCS and s-tDCS conditions (P= 0.0001). In the left leg, the dynamic balance under the a-tDCS condition was significantly higher than MF+s-tDCS (P= 0.025). Anodal stimulation of the DLPFC could be beneficial for the dynamic balance and may have a protective effect against the negative consequence of exhausting activity on the dynamic balance in endurance-trained men.