WHY DO HIIT? If you get your body to work out with 12 to 20 minutes at 84 to 91% of your max heart rate, you will go into a period called EPOC which means excess post-exercise oxygen consumption which allows your body to burn an additional 200 to 400 calories over the next 36 hours doing absolutely nothing at all. This is commonly called after-burn effect. How do you find your max heart rate? You can use a wearable like WHOOP or the Apple Watch. Or, you can use the old-school method called the Karvonen method which is 220 minus your age. #exercise #hiit #afterburn #workout #gym