If you want to get a great cardiovascular workout without spending long hours exercising then high intensity interval training (HIIT) is what you should do. High intensity interval training is a form of cardiovascular exercise where short intense bouts of anaerobic exercise are alternated with longer periods of less intense exercise or recovery repeated again and again. Unlike aerobic exercise high intensity interval training will get the heart rate up close to its maximum if not at maximum.
High intensity interval training is usually performed for 4 to 20 minutes three a week. And, yes four minutes can be enough for you to get a great workout that will lead to improvements in health and fitness.
Benefits of High Intensity Interval Training
- Takes less time than aerobic exercise.
- Improved VO2 max.
- Improved glucose metabolism and insulin sensitivity.
- Improved fat burning and enhance body metabolism.
- Improved hormonal response to exercise.
As the name implies high intensity interval training is performed at high intensity – this means exercising anaerobically which induces physiologic changes not seen at steady and lower paced aerobic exercises. High intensity exercises involve the burning of glucose and glycogen stored in muscle during the exercise leading to improvement in blood glucose control. HIIT creates an oxygen deficit ant that debt is paid off following the exercise by the burning of calories from fat. Metabolism after high intensity interval training stays higher than it does following steady paced aerobics.
High intensity interval training also stimulates the release of growth hormone and testosterone that does not occur with aerobic exercise. Both of these hormones stimulate the loss of fat and the maintenance and growth of lean body mass, aka muscle. Some studies show greater improvement in exercise capacity (VO2 max) following high intensity interval training than seen with aerobic exercise.
How is High Intensity Interval Training Performed?
High intensity interval training is performed on cardiovascular equipment such as treadmill, stationary cycle, elliptical trainers, rowing machines, stair climbers, etc. But, can also be performed using calisthenic exercises like jumping jacks, squat thrusts, push-ups, sit-ups, etc. There are many different HIIT protocols.
One of the more popular protocols is the Tabata Protocol. Tabatas involve high intensity bouts of exercise lasting 20 seconds followed by a ten second recovery period repeated for a total of eight cycles amounting to 4 minutes of exercise.
Another protocol called Sprint 8 involves 30 seconds of intense exercise followed by 90 seconds of recovery performed eight times amounting to a 16 minute workout.
Generally the intense exercise component is performed for a minute or less. You can make up your own protocol and modify it as you become more fit. Initially you will need longer periods of recovery. The recovery should be long enough that you are able to give an all out or near max effort the following cycle otherwise you will find yourself giving a half-hearted attempt during the high intensity component and simply be performing aerobic exercise at a slightly higher intensity than normal.
CAUTION: If you have risk factors for heart disease or have heart disease you should be evaluated and cleared by a physician prior to embarking on a high intensity interval training program. An exercise stress test may needed to be performed to make sure it’s safe for you to engage in high intensity exercise.