High-Intensity Interval Training (HIIT) is an exercise strategy alternating between intense bursts of activity and periods of rest or lower-intensity exercise. Its benefits include significant improvements in cardiovascular fitness, fat loss, and muscle endurance in shorter workout durations. HIIT can also boost the metabolic rate for hours after exercise due to the afterburn effect. Additionally, it's adaptable for various fitness levels and can be performed with minimal to no equipment, making it a practical choice for busy individuals.