Instead of the typical rule of doing at least 30 minutes of moderate exercise five days a week, it’s time to change our thinking. Up your cardio intensity and you can cut your workout time in half…or more. HIIT (High Intensity Interval Training) is an enhanced form of cardiovascular interval training that alternates quick bursts of extremely vigorous exercise with brief, less-intense recovery periods.
Usual HIIT sessions may vary from 4–30 minutes, meaning that it is considered to be an excellent way to maximize a workout that is limited on time. A session often consists of a warm up period of exercise, followed by three to ten repetitions of high intensity exercise, separated by medium intensity exercise for recovery, and ending with a period of cool down exercise. The high intensity exercise should be done at near maximum intensity. The medium exercise should be about 50% intensity. These short, intense workouts provide improved athletic capacity and condition, improved glucose metabolism, and improved fat burning. The super short intervals trigger metabolic changes not seen with more moderate activity making the heart more efficient at pumping oxygen-rich blood to muscles, leading to bigger health gains than you’d get from less intense training –in a fraction of the time of a traditional workout.
There is no specific formula to HIIT. The moves can be equipment-based (running on treadmill) or gear-free (jumping jacks). And it’s adaptable to all fitness levels. If you are a beginner, try alternating 15-30 seconds of moves with 15-30 seconds of rest. For those who are more advanced, you may go hard for one minute, then stop for 30 seconds or less. A common formula involves a 2:1 ratio of work to recovery periods, for example, 30–40 seconds of hard sprinting alternated with 15–20 seconds of jogging or walking. (View the image for a sample HIIT routine).
The American Heart Association supports the power of intense exercise, recommending 150 minutes of moderate activity—or 75 minutes of vigorous activity—per week. The variety provided by interval training seems to be more enjoyable for most people and they tend to stick with their cardio workout for longer extended periods of time.