Acute Effects of Reduced-Exertion High-Intensity Interval Training (REHIT) on Arterial Stiffness in Normal-Weight and Overweight/Obese Individuals

Background: Increased arterial stiffness (AS) following exercise may be associated with acute cardiovascular events. High-intensity exercise may play an important role in an acute increase in AS after exercise. Objectives: This study aimed to examine the acute effect of reduced-exertion high-intensity interval training exercise (REHIT) on AS among individuals with insufficient physical activity compared with that among normal-weight and overweight/obese individuals. Methods: Twenty-four youngadults with low physical activity were divided into the normal-weight group (n=12, age 21.9 ± 0.8 years, body mass index (BMI) 20.97 ± 1.21 kg/m^2) and the overweight/obese group (n = 12, age 21.9 ± 0.5 years, BMI 27.06 ± 5.24 kg/m^2). All participants performed REHIT (20 s 2 all-out sprints on a cycle ergometer for 10 min). Brachial-ankle pulse wave velocity (baPWV), heart rate (HR), blood pressure (BP), rating of perceived exertion (RPE), and affect responses were assessed before and after exercise for 1, 30, and 60 min. Results: Following REHIT, the HR increased, and baPWV decreased, which then returned to baseline at 60 min in both groups. However, there was no significant difference in the HR and baPWV between the normal-weight and overweight/obese groups (P 0.05). The RPE increased significantly in both groups (P 0.05). There was no significant change in the affect responses following REHIT (P 0.05) in both groups. Conclusions: Our main finding was that baPWV did not increase after REHIT in either the normal-weight or overweight/obese groups. This suggests that REHIT can safely be done in physically inactive individuals, both in normal-weight and overweight/obese groups, with no adverse increase in arterial stiffness.