Can Transcranial Direct Current Stimulation Modulate Psychophysiological Response in Sedentary Men during Vigorous Aerobic Exercise?

This study evaluated whether transcranial direct current stimulation (tDCS) could change physiological and psychological responses during vigorous exercise with a constant load. 13 sedentary males (23.0±4.2 years; 25.6±4.2 kg/m²) took part in this randomized, crossed-over, sham-controlled, and double-blinded study. Participants underwent 2 sessions with anodal or sham tDCS (2 mA, 20 min) applied before exercise over the left temporal cortex targeting the left insular cortex. The exercise was performed at vigorous intensity (%HR 81.68±6.37) for 30 min. Heart rate (HR), rating of perceived exertion (RPE) and affective responses (pleasure/displeasure) were recorded at every 5 min. Additionally, heart rate variability (HRV) was measured before, immediately after and 60 min after the end of exercise. A 2-way repeated measure ANOVA showed that tDCS improved HRV neither at rest nor after exercise (p>0.15). Similarly, HR, RPE, and affective responses were not enhanced by tDCS during vigorous exercise (p>0.23). The findings of this study suggest that tCDS does not modulate either HRV at rest nor HR, RPE and affective responses during exercise. Transcranial direct current stimulation's efficiency might depend on the participants' levels of physical fitness and parameters of stimulation (e. g., duration, intensity, and arrangement of electrodes).