What is HIIT?
High Intensity Interval Training (HIIT) is a system of exercise with repeated bouts of short duration, high-intensity intervals followed by lower intensity intervals for recovery. In general, HIIT training calls for challenging exercises such as sprints (whether on a bicycle or running) for short time frames lasting from 10-to-45 seconds.
On a 1-10 scale of perceived exertion, high intensity is anything over an effort level of 8 – where you are completely out of breath; the lower intensity recovery intervals should be an effort level of 6 or below, where you are breathing quick but able to speak.
7 Benefits of HIIT
Here are seven reasons why you can spend less time exercising with HIIT and still get great results:
Using More Oxygen = Burning More Calories
1.Your body burns calories at a rate of 5 calories per liter of oxygen consumed. In general, using exercise to increase the oxygen demands on your body will increase total caloric expenditure both during and after the workout. Short intervals of extremely high-intensity exercise involving a lot of muscle mass require a tremendous amount of oxygen, during both the work interval and the recovery periods.
Burn Calories AFTER the Workout
2. Anaerobic interval training uses the body’s reserves of energy and, after a workout, metabolism stays elevated and continues to burn calories for hours after the workout. This is due to something called the excess post-exercise oxygen consumption (EPOC) effect. With HIIT, you not only burn a lot of calories during the workout, but because of the high intensity you will continue to burn calories as your body replaces energy and repairs muscle proteins damaged during exercise.
Burn Fat AFTER the Workout
3. Not only does your body burn fat for fuel during the workout, during the post-exercise recovery period after HIIT exercise the body will tap into fat stores for the energy required to restore it to its normal resting state.
Become More Efficient at Removing Waste Products
4. HIIT produces a significant amount of metabolic waste, including hydrogen ions and lactic acid. The major reason for an active recovery interval is to remove these waste products to allow the involved muscles to perform the next high-intensity bout. As a result, HIIT workouts train your body to tolerate and quickly recover from periods of high-intensity exercise.
Improve Your Physiology
5. HIIT can promote a number of physiological benefits, such as increased mitochondrial density, improved stroke volume, improved oxidative capacity of muscle and enhanced aerobic efficiency, which was previously thought to occur only as a result of long, slow distance (LSD) training protocols.
Increase Levels of Anabolic Hormones
6. HIIT places a significant amount of metabolic stress on muscle tissue. As part of the repair process, the body will produce elevated levels of human growth hormone, testosterone and insulin-like growth factor-1 to repair damaged muscle proteins, which lead to increases in muscle volume and definition.
Get Results In Less Time
7. Many health clubs and workout studios are applying this science to develop group fitness programs that feature HIIT workouts in formats that are 30 minutes or less. These formats enable you to do more work and receive numerous health benefits in less time.
All of These Benefits Help to Slow the Effects of Aging on Your Body
What is a typical HIIT session like?
A typical HIIT session would call for a warm-up of 5-10 minutes where the intensity gradually increases to an intensity where talking comfortably becomes challenging. Once you are breathing hard and feeling your first sweat, it is time to go to work!
There are a variety of work-recovery models for HIIT; the goal of a workout is to work as hard as possible for each work interval and use the recovery periods to try to catch your breath and get ready for the challenge of the next bout of high intensity work.
- Tabata training, named after the Japanese researcher who created the protocol, is a popular model of HIIT which calls for 20 seconds of hard exercise followed by 10 seconds of recovery, repeated 8 times in a row for a total of 4 minutes; that might not seem like a lot, but when each 20 second bout is performed at your highest effort, the research shows that 4 minutes is all you need for a great workout!
- Another model, 30:30, calls for 30 seconds of high intensity exercise followed by 30 seconds of lower intensity for active recovery repeated for 6-10 minutes (start with 6 and work up from there).
- A third model are Ladders; in a Ladder a 1 minute interval is broken up into two segments, 1 high intensity and one active recovery: for example, 20 seconds of high intensity followed by 40 seconds of active recovery, 30 seconds of high intensity followed by 30 seconds of recovery and finally, 40 seconds of high intensity followed by 20 seconds of active recovery – that is climbing the Ladder to finish the set, reverse the order of the intervals: 40:20, 30:30 and finish with 20:40 (high intensity:low intensity).
In a gym, ergometers like HIIT bikes – that have the moving arms in addition to pedals and Rowing machines are perfect for HIIT intervals. Ergometers work by applying more resistance the harder you work, so as you move fast for an interval there is greater resistance, withOUT having to adjust the equipment. Another option is self-powered treadmills – where your feet provide the energy for the treadmill belt to move. Traditional treadmills and stairclimbers are great for working out but not well suited for HIIT intervals because they require specific settings to change intensity.
You can also get great results by doing bodyweight exercises like fast squats, squat jumps, jumping jacks and other calisthenics. The goal is to move as fast as possible until you are out of breath and exercises that use more muscles means that you will be burning more calories.
One of the most common misperceptions about exercise that it is necessary to spend hours busting your butt and sweating buckets to obtain benefits like weight loss, muscle growth and improved overall health and well-being. Instead of working longer, work smarter by using short intervals of extremely high-intensity exercise. HIIT is extremely effective, but it can place a tremendous amount of stress on the body. Therefore, HIIT should only be performed 2-3 times a week with at least 48 hours between exercise sessions to allow a full recovery of energy stores and to repair muscle tissue.
YES, you CAN exercise the day after a HIIT session, but it should be a low- to moderate-intensity activity and use different muscle groups or movement patterns than those used in the high-intensity workout.
Time is one of our most precious resources and we never seem to have enough of it. Some days, it might be easy to skip a workout because you feel that you might not have enough time to make it worthwhile. But you don’t need to spend hours in the gym to see results—you simply need to make sure that the time you do spend exercising is as efficient and effective as possible!