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Mix It Up with Interval Training

Challenge yourself with bursts of vigorous activity — you may save time to boot.

image of woman's lower legs in sneakers, walking away

When you’re busy, exercise can be hard to fit in. One way to maximize your time is with interval training. It may help you shorten your workouts while keeping you fit. It can also add challenge, variety and fun into your workout.

Interval training is when you do short bursts of high-intensity exercise. You then use the time between each burst to recover. During this recovery time you can either rest or do moderate-intensity exercise.

How can you tell if what you’re doing is at high intensity? Try the talk test. During moderate activity, you should be able to talk but not sing. During high-intensity activity, you won’t be able to say more than a few words at a time.

Some examples of interval workouts are:

  • Vary your walking speed. Add short bursts of brisk walking to your regular route. You can measure these bursts by time or distance. For example, add 30 seconds of quick walking after every five minutes at normal pace. Or pick up the pace every few houses or blocks, and then slow down for your recovery.
  • Vary your running speed. Run hard for one minute and then jog slowly for two minutes. Repeat until you reach your goal time. Or run on a hilly route to include both uphill intervals and downhill recovery time.
  • Vary other speeds. Try a walk-run combination, walking for two minutes, then running for two minutes, and repeat. If you like swimming, do some quick laps in between times of treading water. If you ride a bicycle, peddle at a higher speed for a few blocks to get your heart racing.
  • Do interval circuits at home. Find an exercise circuit you like online or on an app. For example, do a series of squats, then walk in place, then a series of pushups, then rest and repeat. Or run in place during the commercial breaks and credit sequences of your favorite TV show.
  • Take a HIIT class (high-intensity interval training). If you want something more structured, many gyms and exercise clubs offer HIIT classes. Find a gym, trainer, and program that’s right for you.

Some possible benefits of interval training include:

  • Saves time. Most adults should get at least 150 minutes of moderate-intensity aerobic exercise a week. But every minute of high-intensity exercise does as much work as two minutes of moderate-intensity exercise. So, the more high-intensity intervals you include in your week, the less time you may need to spend on exercise overall.
  • Burns more calories. High-intensity activity takes more energy. So, 30 minutes of interval training burns more calories than 30 minutes at a steady pace.  Even after your more intense interval, your body is still using more oxygen. The more oxygen your body uses, the more calories it burns.
  • Improves oxygen use. Bursts of high-intensity exercise may help your heart and lungs use and transport oxygen better. As your body gets better at using oxygen, you may be able to sustain intense bursts for longer time periods.
  • Helps the heart. Interval training may improve your blood pressure and how sensitive you are to insulin. And if you’re at risk for heart disease or type 2 diabetes, the benefits to your heart health may be even greater.
  • Keeps you from getting bored. By adding in some variety, intervals can freshen up your workout routine.

Be careful before amping up your workout

While interval training is safe for most people, it is not right for everyone. It could cause you to injure your muscles, tendons or bones if you rush into it. Talk with your doctor before significantly increasing your activity level. Ask about the amounts and types of activities that may be best for you. Remember, moderation is best when starting an exercise regimen. Start slowly and gradually increase how often, how vigorous and how long you exercise.

Interval training can be an efficient way to improve your fitness. What heart-pumping variety can you mix into your less-intense routines? Going for a walk? Try jogging for a block every time you see a house with a red door. Turn it into a game and interval training can even be fun!

By Susan G. Warner, Contributing Writer

American Council on Exercise. High-intensity interval training: Why it works. Accessed June 25, 2021.
Centers for Disease Control and Prevention. Adding physical activity to your life. Accessed June 25, 2021.
U.S. Department of Health and Human Services. Physical activity guidelines for Americans, 2nd edition. Accessed June 25, 2021.

Last Updated: July, 7 2021