How does HIIT reduce visceral fat?

High-Intensity Interval Training (HIIT) can effectively reduce visceral fat through several key mechanisms. Stacy Sims explains that HIIT generates significant external stress, which promotes adaptations at the molecular level. This stress results in epigenetic changes within the muscles, specifically increasing the number of GLUT4 protein gates that facilitate glucose uptake without the need for insulin. Consequently, the muscles better manage glucose and free fatty acids, reducing their storage as visceral fat.

Moreover, HIIT elicits an acute inflammatory response, which the body learns to manage and overcome. This adaptation is crucial, particularly in women who experience a decline in estrogen, leading to increased visceral fat accumulation. The high-intensity workouts initiate anti-inflammatory responses at the mitochondrial level, which aids in reducing visceral fat while supporting overall metabolic health 1.