In addition to the mental health benefits and strength gains, working out can help you burn serious calories, which is key if you're trying to lose weight. And you don't just burn calories during your workout — your body continues to burn them after exercise. This is known as the EPOC or the afterburn effect.
EPOC stands for excess postexercise oxygen consumption, and many people assume it keeps your body in fat-burning mode for hours after an intense workout. With EPOC, increased oxygen requires increased energy in the body, and increased energy allows you to burn more calories after exercise, Andrew Schuth, AFAA, NASM, AFPA, master instructor at Burn 60, explained.
Reaching EPOC depends on a variety of factors, such as fitness level, age, weight, and height. How long the EPOC effect lasts depends on the intensity of your workout, but in general, it's not nearly as long as many people assume it is.
Although some boutique fitness studios promise EPOC lasts 24 to 48 hours after an intense workout, Andrew said it's much shorter than that: one to two hours, tops.
"The question you might consider asking is if my calorie burning is at its highest peak within the hour after an intense workout, would it make sense that I eat within that hour to replenish needed calories and also burn unwanted ones more efficiently?" he told POPSUGAR. "The answer is yes. I recommend eating within an hour after you work out and to drink lots of water!"
So while your body might not be in total calorie-burning mode for a full day after a hardcore workout, the effects will still last beyond the workout. While your metabolism is still revved up, be sure to refuel with a post-workout meal or snack.