Hemodynamic and autonomic responses after a single session of resistance exercise following anodal motor cortex tDCS

BACKGROUND: Transcranial direct current stimulation (tDCS) seems to modulate cardiac autonomic function and blood pressure (BP) at rest and during exercise. Therefore, it is possible that anodal tDCS could influence post-exercise hypotension. OBJECTIVE: To investigate whether anodal tDCS applied over the motor cortex would affect cardiac autonomic modulation and BP after resistance exercise. METHODS: Twelve apparently healthy young men performed two experimental sessions: anodal tDCS or sham condition followed by resistance exercise. Blood pressure (BP), heart rate (HR), rate-pressure product (RPP), and HR variability (HRV) were obtained before and during post-exercise recovery (at 20 and 60 minutes). RESULTS: Compared to pre-exercise, systolic BP decreased at 20 and at 60 minutes of post-exercise recovery only in anodal tDCS condition(p = 0.03), with no statistical differences in sham condition (p > 0.05). Diastolic and mean BP reduced after both anodal tDCS and sham conditions with no differences between them (P> 0.05). In comparison with anodal tDCS, there were slower HR recovery (tDCS vs. sham: -2 ± 14 vs. 14 ± 8 bpm) and higher RPP (tDCS vs. sham: -1083 ± 1846 vs. 1672 ± 1275 mmHg × bpm) after exercise following sham condition (P< 0.01). No differences were found in any of the HRV analyzed parameters (P> 0.05). CONCLUSION: A single session of primary motor cortex tDCS is capable of decreasing the systolic BP and HR responses, as well as the cardiac work after a resistance exercise session in young normotensive subjects regardless of any changes in cardiac autonomic modulation.