What is the primary characteristic of interval training?

The primary characteristic of interval training is varying intensities during the workout. This method combines periods of high-intensity exercise alternated with periods of lower intensity or rest. This variation helps improve cardiovascular fitness, increases strength and endurance, and can also enhance caloric expenditure and metabolic rate. By incorporating different intensity levels, interval training challenges the body in diverse ways, promoting adaptations that support improved performance over time.

The other options do not accurately describe interval training: constant intensity would not allow for the benefits derived from switching between high and low efforts, while including no rest periods would misrepresent the structure of interval workouts, which rely on recovery intervals to maximize performance in the high-intensity phases. Additionally, a focus solely on strength training does not capture the essence of interval training, which is more commonly associated with a mix of aerobic and anaerobic efforts rather than being limited to strength exercises.