High-intensity interval training performed at 85 to 95% of maximum effort leads to greater caloric expenditure per unit of time compared to lower-intensity exercise.

Study: A comparative analysis of energy expenditure and substrate metabolism in male university students with overweight/obesity: Tabata vs HIIT and MICT

The study shows that super-intense short workouts burn more calories per minute than easier, longer ones, which supports the idea that high-intensity exercise is more efficient for burning calories.

Study: Energy expenditure and EPOC between water-based high-intensity interval training and moderate-intensity continuous training sessions in healthy women

The study looked at intense water workouts and found they burned more calories per minute than steady, moderate ones, which supports the idea that harder workouts burn more calories in less time.

Study: Caloric Expenditure of Aerobic, Resistance, or Combined High-Intensity Interval Training Using a Hydraulic Resistance System in Healthy Men

The study tested a workout with short bursts of all-out effort and found it burned more calories per minute than easier, steady exercises. This supports the idea that harder workouts burn more calories in the same amount of time.