Dynamic Cerebral Autoregulation Is Maintained during High-Intensity Interval Exercise.

Introduction High-intensity interval exercise (HIIE) is more effective at increasing metabolic and cardiovascular health compared with moderate-intensity continuous exercise for patients with cardiovascular disease, but exhaustive high-intensity continuous exercise attenuates dynamic cerebral autoregulation (CA). This study assessed the effect of HIIE on dynamic CA. Methods Nine healthy men (age, 24 +/- 3 yr; mean +/- SD) warmed up at 50%-60% maximal workload (W-max) for 5 min before HIIE including four 4-min bouts of exercise at 80%-90% W-max interspaced by four 3-min bouts at 50% to 60% W-max. Transcranial Doppler determined middle cerebral artery mean blood velocity (MCA V-mean), and brachial artery catheterization determined mean arterial pressure (MAP). Dynamic CA was evaluated by transfer function analysis of changes in MAP and MCA V-mean. Results The HIIE increased MAP (from 92 +/- 9 to 104 +/- 10 mm Hg; P < 0.0125), whereas MCA V-mean did not change. Transfer function phase increased and coherence decreased during HIIE (P < 0.0125 vs rest, respectively), whereas gain was unchanged. Conclusions The results suggest that dynamic CA is unaffected during HIIE, indicating that the brain is protected from fluctuations in MAP. Thus, we propose that HIIE may be beneficial for brain-related health as maintenance of cerebral perfusion in contrast to high-intensity continuous exercise.