HIIT, or High-Intensity Interval Training, is a popular and efficient exercise method that involves alternating short bursts of intense physical activity with brief periods of rest or lower-intensity exercise. It's known for its effectiveness in burning calories, improving cardiovascular fitness, and building strength in a relatively short amount of time.

In a HIIT workout, participants typically engage in a series of exercises or movements that get their heart rates up and challenge various muscle groups. These high-intensity intervals are followed by short recovery periods, allowing the body to partially recover before the next intense bout. The cycle is repeated for a predetermined number of rounds or time, making HIIT workouts highly time-efficient.