Author(s): DELL ANNA, S., BERNARDES, A.G., IVANISKI-MELLO, A., LIBERALI, G., MARTINIS, L., CORREALE, L., PEYRÉ-TARTARUGA, L.A., MACHADO, F.A., COSENTINO, G., DE GIORGIO, A., BALDARI, C., BUZZACHERA, C.F., Institution: ECAMPUS UNIVERSITY, Country: ITALY, Abstract-ID: 1663

INTRODUCTION:
Transcranial direct current stimulation (tDCS) has emerged as a minimally invasive form of cortical stimulation, with exciting potential for exercise performance. While some studies have confirmed the apparent ergogenicity of tDCS during continuous, large muscle-mass exercise, not all findings are consistent. The variable results between tDCS studies may be attributed, at least in part, to differences in exercise intensity. We, therefore, investigated the effects of acute tDCS on exercise tolerance and the physiological responses to heavy- and severe-intensity exercise
METHODS:
Twelve healthy, recreationally active men (mean age ± SD = 25 ± 2 yr, VO2peak 50 ± 8 ml/kg/min) volunteered to participate in this study. All participants were required to report to the laboratory on five separate occasions. On Day 1, they performed a ramp incremental exercise test on an electronically braked cycle ergometer to determine gas exchange threshold (GET), VO2peak, and peak power output (PPO). On Days 2-5, participants received, in a random and crossover order, 20 minutes of brain stimulation of either sham tDCS or anodal tDCS (current intensity: 2 mA) before either heavy- or severe-intensity cycling exercise. Pulmonary exchange and ventilation data, NIRS-derived muscle oxygenation and hemodynamics responses, and surface EMG signals were recorded throughout the exercise bouts. Ratings of perceived exertion (RPE) were also assessed every 2 min in each exercise bout
RESULTS:
No significant effects of brain stimulation on exercise tolerance were observed (261 ± 56 sec and 258 ± 59 sec for sham tDCS and anodal tDCS, respectively; P > 0.05). Anodal tDCS did not induce significant changes in pulmonary gas exchange and ventilation parameters, NIRS-derived muscle oxygenation and hemodynamics responses, or muscle fibre conduction velocity during heavy- and severe-intensity exercise compared to sham tDCS (P > 0.05). Similarly, RPE did not significantly differ between the brain stimulation conditions at any time in both exercise intensities (P > 0.05)
CONCLUSION:
Our findings indicate that acute brain stimulation with anodal tDCS applied over the primary motor cortex (M1) does not appreciably alter physiological responses to heavy- and severe-intensity exercise or improve exercise tolerance in healthy, recreationally active men. These results support the notion that this simple, minimally invasive neuromodulatory technique may not be effective during continuous, high-intensity, large muscle-mass exercise