HIIT or high-intensity interval training is a type of workout that uses periods of alternate intensity. HIIT differs from traditional interval training in that the work periods are much more intense. In addition, traitional interval training can have periods of rest following the work periods. With HIIT, there’s more likely to be low-intensity recovery periods (where you’re still moving but at a low pace) rather than complete stop periods.
HIIT is sometimes also known as High-Intensity Intermittent Exercise (HIIE) because of the rapid change in activity and the intensity used during the workout.
What Makes HIIT Different
One of the most important characteritistics of HIIT is that the workouts rarely last longer than 20-30 minutes. They can even be as short as four minutes if you’re following the Tabata regimen, a specific type of HIIT.
Experts believe that short HIIT workouts can be more effective for fat burning, cardiovascular training and weight loss than traditional workouts that are twice as long. For example, studies have shown that an hour of HIIT is as effective as over five hours of other types of workouts that follow an even level of activity (no ups and downs on intensity). That means people using HIIT obtain the same improvement in endurance and cardio fitness with a much smaller investment of time.
And the improvements are fast. A study published on the International Journal of Sports Physiology and Performance reported that as little as seven sessions of HIIT can improve your endurance performance by an impressive two percent. If you’re working out three times a week, that’s just over two weeks to start seeing significant results.
The reason for the impressive results? HIIT uses a larger percentage of muscles in your body (up to 80 percent of them) when compared with other activities. For example, standard cycling and jogging use just about 40 percent of your muscles during a workout.
How to Do HIIT Right
The good news about HIIT is that you don’t have to do the same workout over and over. In fact, it’s best if you keep switching your activities in order to obtain better results.
HIIT does adhere to some basic principles:
- Always warm up before your first period of high intensity. The warm up can be as short as a minute or it can be several minutes, depending on the length and intensity of the workout to follow.
- HIIT workouts can last anywhere from four to 30 minutes, but not longer. Because of the intense nature of the workout, exercising for a longer period can be too exhausting and could even lead to injury (due to overwhelmed muscles)
- The most common HIIT formula is 2:1. That means if you do two minutes of high-intensity work (like running or sprinting), you follow that with one minute of walking (this would be considered your low-intensity period).Use an interval timer to make sure you get the periods right.
If you are out of shape and need to start slower, you can make your rest periods equal to your high-intensity periods. So can do one minute of running and one minute of walking, for example. As your cardiovascular fitness improves, you can then start adjusting your periods to increase the time you spend on the high-intensity periods. Keep in mind that the goal of HIIT is always to alternate high and low intensity periods. If you don’t do this – or if the periods are too different in length, such as four minutes of hard work but only one of rest – you’ll be compromising the effects of the workout and you might not see the same results.