Effects of single-session anodal transcranial direct current stimulation (tDCS) on cognitive and motor performance in athletes and healthy adults: a systematic review and meta-analysis

This meta-analysis evaluated the effects of single-session anodal transcranial direct current stimulation (a-tDCS) on cognitive and motor performance in athletes and healthy adults. Following PRISMA guidelines, 33 randomized controlled trials published between 2015 and 2025 were synthesized. Single-session a-tDCS was associated with significant improvements in overall motor performance, though substantial heterogeneity was observed (I2 = 62.10%). Strength performance demonstrated the most robust gains (ES = 0.93), followed by explosive power (ES = 0.61) and endurance (ES = 0.41). Conversely, the aggregate effect on cognitive performance—primarily involving the dorsolateral prefrontal cortex (DLPFC)—was trivial and non-significant (ES = 0.28, p = 0.09, I2 = 90.86%). Subgroup analyses revealed that athletes exhibited significantly higher motor responsiveness (ES = 1.03) compared to healthy adults (ES = 0.41), suggesting a potential “neural advantage” in highly trained populations. Dose-response analysis indicated that intensities ≥ 2 mA and durations ≥ 20 min may optimize intervention efficacy. Single-session a-tDCS appears to be an effective aid for motor performance—specifically strength and power—but provides negligible immediate cognitive benefits. The superior responsiveness in athletes suggests elite baseline neural states may amplify neuromodulation effects, though high heterogeneity necessitates a cautious, individualized approach to application.