Transcranial magnetic stimulation-based evaluation of exercise training-induced changes in TMS-derived...

Transcranial magnetic stimulation (TMS) is a well-established, non-invasive technique for assessing motor cortical and corticospinal function, including corticospinal excitability and intracortical inhibition/facilitation. Because commonly used TMS outcomes reflect different neurophysiological mechanisms, they should not be interpreted as a single construct of "cortical plasticity." The effects of structured exercise training on these TMS-derived markers and motor performance in healthy adults remain to be systematically clarified.

This systematic review and meta-analysis synthesized evidence from randomized controlled trials (RCTs) to evaluate the effects of exercise training interventions on TMS-derived neurophysiological markers and motor performance in healthy adults.

Following PRISMA guidelines, we conducted a comprehensive search of PubMed, Web of Science, Embase, and the Cochrane Central Register of Controlled Trials from inception to December 31, 2025. We included RCTs involving healthy adults (≥18 years) that compared structured exercise training interventions (e.g., resistance, aerobic, skill, balance, or combined training) with control conditions and used TMS to assess neurophysiological outcomes. Data were pooled using random-effects meta-analyses to calculate standardized mean differences (Hedges' g). Heterogeneity, exploratory subgroup differences, sensitivity, and publication bias were examined.

Twelve randomized controlled trials met the inclusion criteria. Across these studies, 14 effect sizes were available for TMS-derived neurophysiological markers and 16 effect sizes were available for motor-performance outcomes. The corresponding analytic samples were 137 exercise and 136 control participants for TMS-derived markers, and 154 exercise and 152 control participants for motor performance. Random-effects meta-analysis showed statistically significant pooled effects for TMS-derived neurophysiological markers (Hedges' g = 0.53; 95% CI: 0.10 to 0.95; p < 0.05) and motor performance (Hedges' g = 0.58; 95% CI: 0.23 to 0.93; p < 0.01). Moderate heterogeneity was observed for both outcomes (I² = 64.8% and 54.0%, respectively), and prediction intervals crossed zero. Exploratory subgroup analyses suggested possible differences by intervention duration and training modality, but the duration meta-regression was non-significant and several subgroups had very small K. These subgroup findings should therefore be interpreted as hypothesis-generating rather than confirmatory. Certainty of evidence, assessed via GRADE, was moderate for both outcomes after downgrading for risk of bias, inconsistency, and possible publication bias.

Exercise training interventions may improve motor performance and modulate TMS-derived neurophysiological markers in healthy adults, but the certainty and generalizability of these findings are limited. The heterogeneity of TMS markers, moderate between-study heterogeneity, prediction intervals crossing zero, small subgroup sizes, low statistical power of several trials, and possible small-study effects mean that the pooled results should not be interpreted as uniform or definitive effects. Current evidence is insufficient to establish the superiority of any specific training duration or modality. More standardized, adequately powered RCTs are needed to confirm prescription parameters and long-term effects.

https://www.crd.york.ac.uk/prospero/display_record.php?ID=CRD420261343170, identifier: CRD420261343170.