Effect of Trans Cranial Direct Current Stimulation on Dynamic Balance after Endurance Exhausting Activity in Normobaric Hypoxia

Balance is a key factor for improving exercise performance and preventing sport-related injuries. The objective was to investigate the effect of transcranial direct current stimulation on dynamic balance after performing an exhaustive endurance task in normobaric hypoxia.Methods Fourteen endurance-trained men took part in this study. In three separate experimental sessions, after measuring the dynamic balance at baseline, participants were exposed to hypoxia for 30 min followed by one of the three montages of brain stimulation including 1) anodal stimulation of the M1 region, 2) anodal stimulation of the DLPFC region, and 3) sham stimulation for 20 minutes. Then, participants performed an exhausting cycling task at 60% of peak power output in hypoxia. Immediately after exhaustion, the dynamic balance was measured again. Two-way repeated measures ANOVA was used for statistical analysis. The results showed that after exhaustion under the hypoxic condition, the dynamic balance of the right leg in the DLPFC condition was significantly higher than the dynamic balance in the sham condition (p = 0.042). The results also demonstrated that the dynamic balance of the left leg after exhaustion in hypoxia was significantly higher than that of the sham condition (p = 0.042). We concluded that neuromuscular fatigue and exposure to the hypoxic condition could have a detrimental effect on dynamic balance. Also, it seems that anodal stimulation of the DLPFC area could have a positive effect on the dynamic balance after exhaustion under the hypoxic condition.