Newsflash: The days of spending hours at the gym, flipping through a magazine, pedaling away on the elliptical are over. If you want to get more results, research shows that high-intensity, short-duration is superior for fat loss. It might be counterintuitive to think that LESS time working will actually give you MORE results, but when you look at the science, you’ll understand.

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Photo Credit: Kate Horney

The key is found in the power of EPOC training. In the world of exercise physiology, EPOC stands for excess post-exercise oxygen consumption. Studies show that you can burn extra calories and fat for up to TWO DAYS after your workout when you take advantage of a process called EPOC.

Here’s a simple look at how it works.

  • Exercise uses oxygen. When you exercise, your body uses oxygen to fuel your muscles. Ever noticed how you start breathing harder as your workout gets harder?
  • The harder the exercise, the more oxygen you use. The harder you exercise, the harder you breathe, and the greater the oxygen deficit that you create… bringing your body further from its resting or balanced state.
  • Your body burns fat to return to a state of balance. The oxygen deficit that you create needs to be replenished after you finish your workout so that your body can return back to homeostasis (ultimately, your body’s state of balance). Many reactions (burning both fat and calories) occur in order to bring your body back to homeostasis, or the resting state of balance that you were in pre-workout.

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The key to fat burning is in the work that your body does after the workout is over. Our goal is to create an environment that causes your body to need additional fuel to recover. In addition to the re-oxygenation of blood (the EPOC effect) there are other key reactions that occur as a result intense workouts.

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Photo Credit: Kate Horney

Three ways to burn calories after your workout is over:

  • Your body replenishes muscle glycogen. With the right type of intense, anaerobic workout, your body will use muscle glycogen as a primary source of fuel.  What happens when the fuel has been used?  It must be replaced after the workout, thus requiring calories to refill these stores!
  • Your body returns to resting heart rate. After an intense fat-burning workout, you should feel your heart beating hard. As it’s working to supply blood, nutrients and energy to your muscles, your heart rate will increase. But your heart rate doesn’t immediately return back to its resting rate as soon as your workout is over. Returning to your resting heart rate takes time (and calories) and may last hours after the workout has finished.
  • Your body repairs muscles. Plain and simple, when you work hard enough to break down muscle tissue during your training, your body takes time and needs lots of extra calories to build them back up.

All of these processes need oxygen and fuel to be performed. What kind of fuel? Fat. In addition to burning calories (energy) after your workout, fatty acids are mobilized to help in the recovery process, and that’s why high-intensity, short-duration workouts are superior for fat loss.

Want to learn more? If you need help figuring out what types of high-intensity, short-duration workouts work best, click here for a FREE 7-Day JumpstartAll Skinny Mom readers are invited to give high-intensity, short-duration workouts a try with one week of FREE workouts that you can do right from home!

Kate Horney is a wife, mom (of two cute little boys) and fitness professional who teaches women how to live healthy, happy and balanced lives with real-life training, nutrition and hormone tips for busy moms. Follow Kate on social media at @beyondfitmom and on her website,

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Photo Credit: Kate Horney