"ElectriCise" the brain - effects of transcranial direct current stimulation combined with high-intensity interval training on the electrocortical activity of the motor cortex

Abstract Introduction: Recently, it has been proposed that combining transcranial direct current stimulation (tDCS) with cardiovascular exercise (CE) may lead to positive synergies in motor and cognitive performance due assumed synergistic mechanisms on several brain levels (Steinberg, Pixa & Fregni, 2019). However, the neurophysiological effects of a combined application are currently unknown. Hence, this is first study investigating differences electrocortical activity tDCS during high-intensity interval training (HIIT). Methods: Twenty healthy, right-handed volunteers (mean age 22.65, ±2.83; six males) participated cross-over-design at two experimental sessions one-week wash-out phase. Following three minutes resting state EEG (rsEEGpre), participants performed, based their individual VO2max (spiroergometry) data, HIIT stationary bicycle ergometer (5 min warm-up 40% VO2max, 3 x 90% interspersed 2 60% 5 cool-down 20% VO2max), which either anodal HD-tDCS (1.5 mA, 20 min) or sham was applied counterbalanced randomized order over left primary cortex (C3 surrounded by FC1, FC5, CP1, CP5 as return). In addition, post rsEEG assessed times for up 30 after intervention (rsEEGpost1-6). Results: Scalp maps showed stronger decrease alpha power (8-13 Hz) within active area delayed 25 intervention. observation not supported Bayesian rmANOVA (TIME GROUP BFincl = .056). Discussion: The preliminary results revealed no statistical evidence an additive effect cortical induced HIIT. Further analyses required disentangle local possible remote effects. Since direction, different CE protocols need be investigated further. Research Category Technology Methods Basic Research: 9. Transcranial Direct Current Stimulation Keywords: EEG, Cardiovascular Exercise, Synergies, Neuromodulation