radiantly slim The benefits of high intensity interval coaching continue long after the recreation has been completed. Elevated metabolism lasts for as much as 24 hours after the HIIT treadmill movements, because the body recovers from the pastime by means of targeting fat cells for power. Whether or not working, resting, or drowsing, the body continues to burn calories, because the resting metabolic expense has been improved as a result of the HIIT treadmill exercise.