In overweight and obese male university students, total energy expenditure during and after exercise is not significantly different between one, two, or three Tabata cycles, despite marked differences in fat oxidation, indicating that metabolic efficiency of fat utilization can vary independently of total caloric cost.

After high-intensity exercise, muscle glycogen runs low, forcing the body to switch from burning sugar to burning fat for energy. This switch is strongest when the exercise is intense enough to deplete glycogen but not so intense that it overwhelms the muscles' ability to use fat efficiently. Too little exercise doesn't deplete enough glycogen, and too much exercise builds up too much acid and stress, which slows down fat burning. The body burns the most fat after exercise when the workout hits this sweet spot of intensity and volume.