High-Intensity Interval Training (HIIT) is highly effective for fat loss due to its ability to maximize calorie burn in a short amount of time. HIIT involves alternating between short bursts of intense exercise and rest or low-intensity periods, which increases the body's metabolic rate long after the workout has ended, a phenomenon known as the afterburn effect. This elevated calorie expenditure can significantly aid in fat loss. Furthermore, HIIT improves cardiovascular fitness and muscle retention, allowing individuals to lose fat while maintaining lean muscle mass, making it a popular choice for efficient weight management.