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

Abstract

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).

Effect of transcranial direct current stimulation on supramaximal intermittent exercise performance

“…On the other hand, the RPE was lower only for submaximal intensity. The other two studies do not show RPE reduction and performance improvement 10,12 . They evaluated untrained 12 and physically active 10 subjects, respectively, during submaximal cycling exercise, in an ergometer that they were not familiar with.…”

“…The other two studies do not show RPE reduction and performance improvement 10,12 . They evaluated untrained 12 and physically active 10 subjects, respectively, during submaximal cycling exercise, in an ergometer that they were not familiar with. The time trial of 20-km and time to exhaustion at 75% of maximum power were not improved 10 , nor was the pleasure and displeasure sensations during 30 minutes of 4 Motriz, Rio Claro, v. 25 cycling at 82% of heart rate maximum 12 .…”

“…A consensus between these approaches is that when performance improves by training or ergogenic strategies, the RPE is lower than before 33 . However, the exercise intensity could help explain the absence of RPE response after tDCS 12 . Another explanation for the absence of RPE response is the brain region stimulated.…”

“…The system was capable of generating 10 mA and was controlled by a professional digital multimeter (DT832, Weihua Electronic Co., Ltd, China) with a standard error of ± 1.5%. This device has been used in other studies 5,12,22 A pair of sponge electrodes humidified with saline (150 mmol of NaCl diluted in water) was placed over silicone electrodes (35 cm 2 ). The electrodes were fixed on the head with a silicone cap.…”

“…The field of research involving neuromodulation and different exercise model is still poor, only a few studies have verified the effect of tDCS in cycling exercise with incremental-load, 5 constant-load [8][9][10][11][12][13] or supramaximal intensity 14 . Here, we aimed to know if tDCS could improve physical performance for supramaximal intermittent cycling exercise.…”