What Is HIIT?

It's time to HIIT it! Rising slowing in popularity for a while, HIIT workouts first made the American College of Sports Medicine's list of fitness trends back in 2014, and they are still going strong. If you haven't jumped on the HIIT bandwagon yet, here's what you need to know.

POPSUGAR Photography | Benjamin Stone

What Is HIIT?

The accurately poetic acronym HIIT stands for high-intensity interval training. A HIIT workout mixes shorts bursts of activity with even shorter rest periods. Ideally, you work to your maximum capacity during the short bursts of activity, hence the use of "high intensity" to describe those intervals. Because you are pushing your limits, these workouts tend be shorter, rarely passing the 30-minute mark.

HIIT workouts are scalable to any fitness level, making it a popular format for group fitness classes. Your goal is push yourself to 90 percent of your personal max in the intense intervals, and this varies among individuals. Using the rate of perceived exertion scale to measure your efforts helps keep the workout individualized.

You can do a HIIT workout with almost any type of activity, including running, swimming, and cycling, as well as strength training with exercises like burpees, squats, and push-ups. HIIT is flexible and you can create different formulas for the work-to-rest ratio, but the most popular is 2:1. For example, you work for 40 seconds at your max and rest for 20, repeating this pattern for five to 10 sets. The Tabata Protocol might be the most well-known HIIT workout. Its eight rounds of 20-second intervals followed by 10 seconds of rest make it one of the hardest four-minute workouts you've ever done.

The Benefits

  • HIIT workouts are efficient; since you're working to your max, you burn more calories in less time.
  • Adding intervals into your workouts helps you burn more fat during your sweat session.
  • Interval workouts, compared to steady-paced ones, have a higher afterburn effect, meaning you continue to burn calories after your workout is over for a longer period of time.
  • HIIT workouts also increase your endurance. So when you do go for a long, steady-paced run, you can go further.
  • Health-wise, intervals improve your cardiovascular health, cholesterol profile, and insulin sensitivity (which helps fight type 2 diabetes).

HIIT Workouts to Try

Here are some of our favorite HIIT workouts:

Since HIIT workouts are so vigorous, it's best to do no more than two a week and avoid doing back-to-back HIIT workouts. You need to give your body time to recover to truly reap the benefits of these workouts so you can go hard at your next sweat sesh.