High-Intensity Interval Training Protocols Variation Response to Immune Parameters and Cardiovascular Risk Factors: A Scoping Review

High-intensity interval training (HIIT) is a form of interval training alternating short periods of intense anaerobic exercise with less intense recovery intervals. HIIT has gained much attention around the world as a method to reduce time commitment for exercising which minimize the barrier of being physically inactive. In addition, various research reported that HIIT produced similar benefits to traditional exercise in improving health status as little as two weeks. There are various protocols of HIIT such as Power 90 Extreme (P90X), Tabata, Spinning, ISANITY, CrossFit, and Sprint 8. However, the findings on which HIIT protocols offer the most effective methods in the role of improving immune system and inhibiting cardiovascular disease (CVD) development are not well explained. It is also uncertain on which protocols, type of exercise movements, duration and volume constitute optimal training for inducing the desired change in immune function and CVD risk factors. The main aim on this study is to provide a brief summary of the current literature regarding the HIIT protocols variation through the immune functional perspectives and its role in decreasing the risk of CVD risk factors.