What exercise modality is characterized by high-intensity bouts followed by rest or low-intensity recovery?

High-Intensity Interval Training (HIIT) is characterized by alternating high-intensity bouts of exercise with periods of rest or lower-intensity recovery. This approach to training is designed to maximize cardiovascular benefits and increase metabolic rate in a shorter amount of time compared to traditional steady-state cardio workouts. The intensity during the high bouts challenges the body, pushing it to adapt and improve fitness levels, while the recovery periods allow for a brief respite, making the workout more sustainable over time.

This unique structure of alternating between intense effort and recovery is what sets HIIT apart, making it particularly efficient for fat loss and increasing endurance. Strength training primarily focuses on building muscle and does not typically involve the same kind of interval-based format. Yoga and Pilates emphasize flexibility, balance, and core strength, with less emphasis on high-intensity performance and recovery intervals. Therefore, HIIT stands out as the clear answer to the question.