High-intensity interval training is an exercise format that alternates periods of short, intense exercises with less intense recovery periods.  HIIT classes at the Y give participants an efficient strength and cardio workout filled with loads of energy and encouragement. The goal to reach an anaerobic state, increasing metabolism for 24 -72 hours after the workout. Although HIIT classes by name are high – intense, all fitness levels are welcomed. Exercises cab be modified to match your abilities and comfort.