Transcranial Direct Current Stimulation Over Premotor Cortex Improves Perceptual Anticipation In High-level Soccer Athletes After Sports Fatigue

Sports fatigue (SF) impairs the perceptual anticipation performance (PAP) of soccer athletes. Transcranial direct current stimulation (tDCS) can improve PAP by modulating brain regions (e.g., dorsal premotor cortex, PMd) related to the action observation network. PURPOSE: This study aimed to investigate the effect of tDCS over left PMd on improving the decline of PAP in soccer athletes after SF. METHODS: This study utilized a repeated measures design. A total of 24 high-level soccer athletes ( age, 20.1 ± 1.8 yrs, training experience, 9.9 ± 2.9 yrs, 6 females, non-goalkeeper) in a public university in China voluntarily participated in this study. PAP consisted of a visual search task(VST), a prediction of soccer breakthrough task (PSBT), and a prediction of soccer penalty task (PSPT). Two-way repeated-measures analyses of variance (ANOVAs) with the within-subject factors session (sham-tDCS and anodal-tDCS), and 3 task difficulties (VST ~ 3, 6, 9 graphic stimuli; PSBT~-80 ms, -160 ms, -240 ms, touching ball as 0 ms; PSPT~0 ms, -80 ms, -160 ms, touching ball as 0 ms ) were used for the dependent variables reaction time (RT) and accuracy (ACC). For the formal experiment, subjects first performed a 60% Powermax riding to induce SF and collected heart rate (HR), rating of perceived exertion scale (RPE), riding duration (RD), and blood lactate (Bla), followed by 2 mA anodal-tDCS and sham-tDCS for 10 min in a balanced manner, and the intervention ended with task tests in randomized order. RESULTS: For the SF, there was no significant difference between anodal-tDCS (RD, 49.7 ± 8.3 min, HR, 174.1 ± 11.0 bpm, RPE, 19.8 ± 0.3, Bla, 8.7 ± 2.6 mmol/L) and sham-tDCS (RD, 50.2 ± 6.5 min, HR, 173.7 ± 14.9 bpm, RPE, 20.0 ± 0.0, Bla, 8.9 ± 4.2 mmol/L) session. For the VST, anodal-tDCS session had faster RT compared to sham-tDCS session at 3 (P = 0.023, Cohen's d = 0.34) and 6 (P = 0.017, Cohen's d = 0.29) quantitative conditions. For the PSBT, anodal-tDCS session had higher ACC compared to sham-tDCS session in the condition of 240 ms (P < 0.001, Cohen's d = 0.52). There were no significant differences between real and sham tDCS sessions on VST’s ACC, PSBT’s RT, and PSPT’s ACC and RT. CONCLUSIONS: Anodal tDCS (2 mA, 10 min) over left PMd can effectively improve the perceptual anticipation of high-level soccer athletes after sports fatigue. This research was funded by Humanities and Social Sciences Research Funds of the Ministry of Education of China (22YJCZH136), the Fundamental Research Funds for the Central Universities (2022QN011), the Research Foundation for Advanced Talents of Beijing Sport University.