Effects of Transcranial Direct Current Stimulation on Cycling Time Trial Performance and Prefrontal Cortex Activation

Background: Transcranial direct current stimulation (tDCS) is a neuromodulatory technique that delivers low levels of a constant current via scalp electrodes to specifically targeted areas of the brain. The effects of tDCS on whole-body exercise performance has been of interest in recent literature. The purpose of the current investigation was to investigate if tDCS, administered via Halo Sport, influences time trial performance in trained cyclists, and if changes in exercise performance are associated with prefrontal cortex (PFC) activation and/or muscle oxygenation (SmO2). Methods: Twelve recreationally trained cyclists volunteered to participate in a crossover study design involving two 10-kilometer time trials following 20 min of tDCS or a sham condition. Results: t-tests showed there was no significant difference in performance (time to completion) or physiological measures (blood lactate (BL) concentration, heart rate (HR), SmO2, PFC oxygenation) between the Halo and sham conditions. Conclusions: These results indicate that the application of tDCS via Halo Sport does not induce changes in exercise performance or related physiological parameters during a 10-kilometer cycling time trial.