Personal trainer Ashley Borden has worked with a range of celebrities, including Ryan Gosling, Reese Witherspoon, and Christina Aguilera. She clearly knows her stuff, and she’s sharing her tips in a new interview with Healthista.
Among Borden’s go-to exercise methods is high-intensity interval training, better known as HIIT, a training method that encourages people to work out at 100-percent intensity for quick bursts, followed by short periods of recovery. “It’s efficient, burns fat, [helps you gain] muscle, and you can do it anywhere without equipment—just your body weight,” Borden says.
But there’s an additional benefit of HIIT that happens long after people stop sweating. “HIIT also allows for a fantastic postexercise metabolic boost called the EPOC effect,” Borden says. Meaning, after a HIIT training session, your body continues to burn extra calories.
It sounds too good to be true, but Albert Matheny, M.S., R.D., C.S.C.S., of SoHo Strength Lab and Promix Nutrition, tells SELF that it’s legitimate. EPOC stands for Excess Postexercise Oxygen Consumption, which basically means that your body’s oxygen consumption goes up after you do a hard workout.
“Your body is working to adapt to the exercise it performed,” Matheny explains. The increased metabolism is a result of your body replenishing the phosphagen system (your body’s metabolic system responsible for short bursts of exercise), oxidizing lactic acid, and the increase in body temperature that you get from exercise, he says.
Doug Sklar, a certified personal trainer and founder of New York City–based fitness training studio PhilathroFIT, tells SELF this basically means that your body is burning more calories after exercise than it was before in an attempt to return to its normal resting state. “A common analogy to describe the EPOC effect is how a car engine stays warm for a while after shutting the car off, before returning to its normal, nonrunning temperature,” he explains.
Due to various factors, it’s difficult to gauge exactly how many calories you’ll burn during EPOC, but Sklar says it’s likely to be less than 15 percent of the total calories you burn overall from your workout. The exact amount varies from person to person, and it’s usually determined by how much muscle mass someone has.
People who are very muscular will burn more calories from EPOC than those with less muscle. The length of your EPOC also depends on how intensely you exercised, Sklar says—the higher the intensity, the longer the EPOC effect.
Although HIIT is great for EPOC, it isn’t the only exercise that has this result. Matheny says heavy lifting can have the same impact, as can jumping rope. Full-body strength training with little rest will create the biggest EPOC effect, Sklar says, adding that the reverse is also true: Lower-intensity exercises, like running at a steady pace, won’t produce a strong EPOC effect.
But Matheny stresses that it’s important not to do HIIT or high-intensity exercises every day, since pushing yourself to the limit daily can lead to overtraining and injury. “It is only a matter of time,” he says.
However, if you want to mix up your workouts and are looking for a way to burn extra calories, it’s good to know that doing high-intensity exercises may help. Just keep this in mind, per Sklar: “The higher the intensity of your chosen exercise, the more significant the EPOC.”