高強度間歇運動對大腦血流及認知功能急性反應之探討

Acute physiological responses of cerebral blood flow and cognitive function to high-intensity interval exercise

高強度間歇運動 （high intensity interval exercise, HIIE） 的特徵是短時間、多回合的高強度運 動，回合間穿插恢復時間來進行。已知高強度間歇運動能有效提升有氧耐力、肌力及增進心血管健 康、促進合成代謝激素分泌。但是，關於間歇運動對大腦血流調控與認知功能之潛在影響與相互關 連性，目前探討的研究仍然不多。因此，本文將以高強度間歇運動對大腦血流及認知功能急性反應 為主軸，透過文獻回顧方式整合現有科學證據，逐節探討高強度間歇運動之健康效益、間歇運動型 態差異對認知功能之影響、急性運動對認知功能與大腦血流之關聯性等議題|同時，進一步評析可 能涉入之生理機制。文獻回顧指出，強度在 75%以上之高強度運動能促進腦血管生成，增加大腦血 流量、促進腦部神經細胞活動，進而增進認知行為表現及學習力，對認知功能及大腦血流有正向效 益。然而，當運動強度過高，較容易因神經疲勞產生反效果。而對於不同時間間隔運動模式對腦血 流及認知功能的影響研究仍有限，且在運動後提升大腦血流量是否能一併提升認知功能現今也未有 定論。對此，建議未來研究，可設計不同強度或不同持續時間之高強度間歇運動，以期更有利於此 運動增強認知功能及大腦血流之效益。

High intensity interval exercise (HIIE) is a short-term, multi-round, high-intensity exercise with interpolated recovery time between rounds. HIIE has been reported to effectively improve aerobic fitness, muscle strength, cardiovascular fitness, and increase releasing of anabolic hormones. But, there are still limited studies investigating the acute effects of high-intensity interval exercise on the regulations of cerebral hemodynamics and cognitive functions, and the interactive relationships among these are still rarely discussed. Therefore, through integrating currently existing literature, this review here focus on the health benefits of high-intensity exercise, impacts of the varied setting of interval exercise on cognitive performance and cerebral hemodynamics regulation. Additionally, the involved underlying physiological mechanisms are discussed as well. Recent literature suggests that the exercise intensity above 75% maximal effort can increase cerebral angiogenesis, cerebral blood flow, promote brain neurons activity, and thus enhance cognitive performance and learning| in contrast, when the exercise intensity reaches to certain levels (e.g. >85% VO2max), it is more likely to induce adverse effects on cognitive performance due to neural fatigue. However, there are very limited investigations focusing on the impacts of different interval exercise models on the regulations of cerebral hemodynamics and cognition. Moreover, it is still controversial whether the enhancing cognitive function in response to acute exercise is directly mediated through the increase in cerebral blood flow. Altogether, we recommend that future studies can design HIIE with different intensities or durations, which may help to elucidate the underlying mechanisms for the benefits of exercise-enhanced cognitive function and cerebral blood flow.