From this article, Impact of exercise intensity on body fatness and skeletal muscle metabolism, this quote:
“The metabolic adaptations taking place in the skeletal muscle in response to the HIIT program appear to favor the process of lipid oxidation”.
“Despite its lower energy cost, the High Intensity Interval Training (HIIT) program induced a more pronounced reduction in subcutaneous adiposity compared with the ET program. When corrected for the energy cost of training, the decrease in the sum of six subcutaneous skinfolds induced by the HIIT program was ninefold greater than by the endurance training (ET) program”
If you want to get the most for your minimal free time or if you hate to exercise HIIT will burn more calories for the time spent. Calories are burned four ways with this workout: