Nine men each completed three 2-day trials and each person served as their own control. Subjects rested (control), walked briskly for 30 min (walking) or performed 5×30 s maximal sprints (high-intensity).

Another study found that the beneficial effects of high-intensity interval training on postprandial triglyceride levels were abolished 2 days after exercise. This suggests that although high-intensity exercise may be a time-efficient tool that is useful for the prevention of heart disease, it may have to be performed 3-4 times a week to be effective.