High-intensity interval training (HIIT) significantly boosts metabolism through increased caloric burn during and after workouts. This "afterburn" effect, known as excess post-exercise oxygen consumption (EPOC), leads to elevated heart rates and energy expenditure, promoting fat loss. HIIT also enhances insulin sensitivity and aerobic capacity, improving overall metabolic function. Furthermore, this training approach can lead to adaptations that improve the body's ability to utilize fat as fuel, making it an efficient method for weight management and metabolic health.