Current concepts of high intensity interval training: a clinical commentary

Abstract Regular exercise produces a variety of physiological changes that improve exercise capacity and health, regardless of age, gender, or chronic illness status. Despite widespread physical inactivity due to time restrictions, High-Intensity Interval Training (HIIT) has evolved as a popular and time-saving strategy for strenuous exercise that improves physical fitness by increasing maximum oxygen uptake (VO 2max ) and muscle power. HIIT, which consists of brief bursts of intense activity at or near peak effort interspersed with intervals of rest or low-intensity exercise, causes a variety of physiological changes that improve exercise capacity and metabolic health in both clinical and healthy populations. Given the expanding scientific understanding and broad use of HIIT, this clinical commentary seeks to thoroughly investigate its definition, parameters, scientific foundations, multifarious benefits, and evidence across varied groups and situations.