Acute effects of anodal transcranial direct current stimulation on endurance and maximal voluntary contraction in lower limbs: a systematic review and meta-analysis.

Abstract

Purpose: To examine the effects of single-dose anodal tDCS on isometric maximal voluntary contraction (MVC) and isometric endurance performance in lower limb exercises with healthy adults.

Methods: For this systematic review and meta-analysis, we searched PubMed, ISI Web of Science, Scopus, and CINAHL for studies published between database inception and June 11, 2024. All randomized controlled trials on anodal tDCS interventions for MVC and isometric endurance in lower limb exercises were included, with no date restrictions. The quality of the evidence was assessed using the Jadad Scale, and the certainty of evidence was assessed using the Grading of Recommendations Assessment, Development, and Evaluation approach. The Open Science Framework registered the protocol in June 2024 (DOI https://doi.org/10.17605/OSF.IO/AG93M ).

Results: 20 interventions were included, comprising 15 for MVC and 5 for 'Time to Task Failure' (TTF), which refers to isometric endurance performance measured in seconds. The findings showed no difference in the MVC (SMD = 0.06; 95% CI = - 0.14, 0.25; P = 0.57) and TTF performance (WMD = 0.07; 95% CI = - 0.26, 0.40; P = 0.68).

Conclusion: The current meta-analysis indicated that anodal tDCS did not increase isometric MVC and isometric endurance performance in lower limb exercises in healthy adults.