HIIT, or High-Intensity Interval Training, is a popular fitness method that alternates periods of intense exercise with short recovery phases. It is favored due to its time efficiency and ability to provoke significant calorie burn in a short duration. HIIT improves cardiovascular fitness, enhances metabolic rate, and builds strength. Many people enjoy it because of its flexibility and challenge, allowing for variations in exercises and adaptability to different fitness levels. Overall, HIIT can improve physical performance and make workouts feel less monotonous.