Dual-site M1-DLPFC anodal transcranial direct current stimulation is superior to single-site stimulation in improving self-paced endurance performance of cyclists.

Endurance performance relies on motor and executive control, mediated by the primary motor cortex (M1) and dorsolateral prefrontal cortex (DLPFC). We hypothesized that dual-site anodal transcranial direct current stimulation (M1-DLPFC) would yield stronger effects on endurance performance, psychophysiological responses, and executive function during self-paced endurance task than single-site stimulation. Fourteen trained male cyclists participated in four randomized, double-blind, sham-controlled transcranial direct current stimulation sessions (M1, DLPFC, dual-site M1-DLPFC, sham; 2 mA, 20 min). After stimulation, they performed a 15-km self-paced cycling time trial. Heart rate, rating of perceived exertion, pleasure, and arousal were measured every 3 km, and executive function every 4 km. Endurance performance was defined as the time to completion. Dual-site M1-DLPFC was superior to M1, DLPFC, and sham in endurance performance. Both single-site stimulations also improved completion time relative to sham. Dual-site stimulation lowered heart rate versus sham and elicited the lowest ratings of perceived exertion, differing significantly from both single-site and sham conditions. Dual-site stimulation further elicited higher pleasure sensation and felt arousal at several distance points compared with sham and single-site conditions. It yielded superior cognitive performance in the backward counting task compared with all other conditions. Concurrent M1-DLPFC anodal transcranial direct current stimulation enhanced self-paced endurance performance, reduced perceived exertion, improved affective responses, and preserved cognitive function during prolonged exertion more effectively than single-site stimulation. Clinical trial registry: IRCT20230729058958N1, registration date: 03.08.2023.