Transcranial direct current stimulation to enhance athletic performance outcome in experienced bodybuilders.

Transcranial direct current stimulation (tDCS) is currently under investigation as a promising technique for enhancement of athletic performance through modulating cortical excitability. Through consecutive randomization, 12 experienced bodybuilders were randomly assigned to two arms receiving either sham or real tDCS over the primary motor cortex (leg area) and left temporal cortex (T3) for 13 minutes in the first session. After 72 hours, both groups received the inverse stimulation. After the brain stimulation, cerebral hemodynamic response (using frontopolar hemoencephalography) was examined upon taking three computer-based cognitive tasks i.e. reasoning, memory and verbal ability using the Cambridge Brain Science-Cognitive Platform. Subsequently, the bodybuilders performed knee extension exercise while performance indicators including one-repetition maximum (1RM), muscular endurance (SEI), heart rate (ECG), motivation (VAS), surface electromyography over quadriceps femoris muscle (sEMG) and perceived exertion (RPE) were evaluated. The real tDCS vs. sham group showed decreased RPE and HR mean scores by 14.2% and 4.9%, respectively. Regarding muscular strength, endurance, and electrical activity, the 1RM, SEI, and sEMG factors improved by 4.4%, 16.9%, and % 5.8, respectively. Meanwhile, compared to sham, real tDCS did not affect the athletes' motivation. Incidentally, it turned out that subjects who underwent T3 anodal stimulation outperformed in memory (p = 0.02) and verbal functions (0.02) as well as their corresponding frontopolar hemodynamic response [(memory HEG (p = 0.001) and verbal HEG (p = 0.003)]. Our findings suggest that simultaneous tDCS-induced excitation over the M1 leg area and left temporal area may potentially improve the overall athletic performance in experienced bodybuilders (Trial registration: IRCT20181104041543N1, Registered on 4 Nov. 2018, retrospectively registered).

Electrophysiological modulation and cognitive-verbal enhancement by multi-session Broca's stimulation: a quantitative EEG transcranial direct current stimulation based investigation.

To evaluate transcranial direct current stimulation-induced changes in resting state quantitative EEG and cognitive-verbal performance of second language learners, 16 healthy individuals were randomly recruited to sham and real transcranial direct current stimulation groups receiving eight sessions of second language instruction accompanied by a 2 mA transcranial direct current stimulation over Broca's area with the cathode placed over the left arm. Quantitative EEG was recorded during the resting state after the stimulation session and second language instruction. Reduced theta activity at Fp1, F7, F3, and T5 caused by the stimulus current was reported. Multisession stimulation resulted in a significant increase in current density for beta power (25 Hz) in the language network. Cognitive-verbal pre-post stimulation performances suggest that anodal vs. sham transcranial direct current stimulation significantly improved the subjects test score on digit span, a cognitive-verbal ability. It is concluded that transcranial direct current stimulation of Broca's area increase cognitive-verbal performance by modulating brain electrical activity in language-related regions.

Transcranial Direct Current Stimulation to Assist Experienced Pistol Shooters in Gaining Even-Better Performance Scores.

Recently, brain stimulation has been considered as a promising method for the empowerment of athletes' performance. This study recruited 16 pistol shooters who were randomly assigned to two arms, including the control receiving no intervention and the experimental group receiving either sham or real transcranial direct current stimulation (tDCS), i.e., anodal stimulation and cathodal suppression over the cerebellar and dorsolateral prefrontal cortex (DLPFC) regions, respectively. Our outcome measures were the score and latency to shooting, as well as number of errors and task time in the dynamic tremor and mirror-tracing tasks. Our findings suggested that tDCS vs. sham improves the average shooting score in pistol shooters by 2.3% ± 0.65 (mean ± SEM, p = 0.018). Furthermore, the bullet hole distance from the Air Pistol Target center was found to be significantly shorter in the experimental (tDCS) group (p = 0.02). In the control group, no significant difference was noted between the shooting scores of shooters over the consecutive two sessions. In terms of latency to shooting, no significant difference was noted within groups between both sessions. However, for the dynamic tremor task outcome, there were significantly less errors after real tDCS than after sham stimulation. In addition, the results of the mirror-tracing task in the tDCS group showed significant differences between the sham and real-tDCS sessions favoring the real-tDCS session (p = 0.001). Therefore, concurrent suppression of dlPFC and stimulation of cerebellum through tDCS may increase shooting scores in experienced pistol shooters.