High-Intensity Interval Training (HIIT)

Two women sprinting

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High-intensity interval training (HIIT) is a great way to bump up your cardio and strength workouts by adding intensity, variety, and a calorie-burning boost. So, what exactly is HIIT training? It's a type of interval training in which you alternate short, very high-intensity intervals with longer, slower recovery intervals.

The idea is to work in the upper percentages of your target heart rate zone, or around a 9 out of 10 on the perceived exertion scale, meaning you go as hard as you can during the work intervals. This intensive effort takes you into your anaerobic zone, a level so high that your body can't take in enough oxygen to the generate energy it needs for the activity.

It's kind of like being on Mars without your helmet—something you could only do for a very short period of time. This type of exercise forces your body to become more efficient and use stored energy for fuel, making it a great way to enhance your fitness level, build muscle, and burn fat.

Benefits of HIIT

This type of training has been used by athletes to improve performance, but it's also been shown to benefit the average exerciser. Here are just some of the benefits of HIIT training:

Boosts Performance

HIIT improves performance. Put a little HIIT into your routine and you'll notice a distinct difference in your other workouts, namely that you have more stamina and endurance.

Reduces Fat and Spurs Weight Loss

HITT also helps you burn more fat. This is where the real benefits come in, especially if you want to lose weight. Studies have shown that HIIT training results in more weight loss than steady, lower-intensity workouts. It also allows more fat to be burned within the muscles being used—pretty amazing since we've always found that spot reduction doesn't work.

Improves Insulin Sensitivity

Studies show that HIIT dramatically improves insulin sensitivity, which is an important component in the body's process of regulating blood sugar levels. Those with insulin resistance (the opposite of insulin sensitivity) are more prone to serious health complications such as diabetes.

Shorter Workouts

Your workouts are shorter. A typical HIIT workout usually lasts about 15 to 30 minutes and involves a 2:1 ratio, meaning your recovery intervals are twice as long as the work intervals. An example would be 5 to 10 high-intensity sprints (working at level 8 to 9 on the perceived exertion chart) lasting 30 to 60 seconds, interspersed with recovery intervals of 1 to 2 minutes (working at level 4 to 5).

Studies show that one of the most common reasons cited for not exercising is time, so HIIT may be a good option for many.

Creating a Workout

Creating your own HIIT workout is simple. Basically, after a thorough warm-up, you choose a very high-intensity exercise, such as burpees, sprinting all-out, or cycling as fast as you can. Then, do about 30 seconds of your all-out exercise, followed by a recovery exercise, such as jogging or lunges, for about one minute, repeating those intervals for about 20 minutes or so, depending on your fitness level.

If you're a beginner, going all-out is not recommended and you probably won't like it. But one great thing with HIIT is that you determine your intensity level—start by pushing yourself a bit (but not too much). Then, aim to add intensity as your fitness level improves.

  • Beyond that, you can try one or more of the following workouts, which really take you into your anaerobic zone for killer, calorie-burning workouts.
  • High-Intensity Sprint Intervals: 30-minute workout adaptable for any type of cardio
  • 30-60-90 Mixed Interval Workout: 39-minute workout suitable for any type of cardio
1 Source
Verywell Fit uses only high-quality sources, including peer-reviewed studies, to support the facts within our articles. Read our editorial process to learn more about how we fact-check and keep our content accurate, reliable, and trustworthy.
  1. Boutcher SH. High-intensity intermittent exercise and fat lossJ Obes. 2011;2011:868305. doi:10.1155/2011/868305

By Paige Waehner, CPT
Paige Waehner is a certified personal trainer, author of the "Guide to Become a Personal Trainer," and co-author of "The Buzz on Exercise & Fitness."