HIIT is superior than MICT on cardiometabolic health during training and detraining

Abstract

Purpose

This study investigated the cardiometabolic health of overweight/obese untrained individuals in response to 8 weeks of HIIT and MICT using a field approach, and to 4 weeks of training cessation (TC).

Methods

Twenty-two subjects performed 8 weeks of moderate intensity continuous training (MICT—n = 11) or high-intensity interval training (HIIT—n = 11) (outdoor running), followed by 4 weeks of TC. Cardiorespiratory fitness, body composition, arterial blood pressure, glucose metabolism and blood lipids were measured pre-training (PRE), post-training (POST) and TC.

Results

HIIT improved eight indicators of cardiometabolic health ($V{\text{O}}_{2\max }$, BMI, body fat, visceral fat, systolic blood pressure, total cholesterol, fasting glucose and triglycerides—p  < 0.05) while MICT only three ($V{\text{O}}_{2\max }$, BMI, and visceral fat—p  < 0.05). After 4 weeks of TC, four positive adaptations from HIIT were negatively affected ( $V{\text{O}}_{2\max }$, visceral fat, systolic blood pressure and total cholesterol—p  < 0.05) and three in the MICT group ($V{\text{O}}_{2\max }$, BMI and visceral fat, p  < 0.05).

Conclusion

Eight weeks of HIIT performed in a real-world setting promoted a greater number of positive adaptations in cardiometabolic health of individuals with overweight/obese compared to MICT. Most of the positive effects of the HIIT protocol were also found to be longer lasting and maintained after the suspension of high-intensity interval running for 4 weeks. Conversely, all positive effects of MICT protocols were reversed after TC.