Abstract
Evidence-based guidelines suggest that High-Intensity Interval Training (HIIT) is more beneficial than aerobic exercise for patients with cardiovascular disease, but the differences in underlying pathophysiological mechanisms require further confirmation. The comparison between HIIT and Moderate-Intensity Continuous Training (MICT) in regulating vascular dysfunction in spontaneously hypertensive rats (SHR), along with their underlying mechanisms, has not been previously reported. The purpose of this study is to provide an experimental basis for exercise prescription therapy in hypertensive patients. In this study, six-week-old male SHR were randomly assigned to a HIIT group, MICT group, or sedentary group. Wistar Kyoto rats (WKY) of the same age were used as the control group. The weight, heart rate, and blood pressure of the rats were monitored weekly throughout twelve weeks of treadmill training. At the end of the protocol, serum and aortic vascular tissues were collected for further vascular function tests and molecular and biochemical analyses. The results show that MICT is more favorable for weight control than HIIT, while both forms of exercise offer equal protection against hypertension. However, MICT demonstrates a greater benefit in preserving vascular morphology, whereas HIIT is more effective in reducing oxidative stress. Both HIIT and MICT ameliorate vascular dysfunction in SHR by suppressing nucleotide-binding domain and leucine-rich repeat pyrin-domain containing protein 3 (NLRP3)-induced pyroptosis. The superior effect of HIIT on vascular dysfunction may be related to the inhibition of oxidative stress injury through AMPKα-SIRT1 activation. This study provides insight into the dose-effect relationship of exercise for cardiovascular health and offers foundational evidence for the development of exercise prescription therapies.