Keto Belly Burn Fat Doesn't matter what you do, do intervals where you do it hard and fast and then follow those with intervals where you do it slow and easy. This goes with running and walking, bike riding, the stairstepper, the elliptical, and whatever else you can think of. By doing fast intervals followed by slow intervals, you not only burn fat during the exercise, your body burns fast for up to 18 hours NON-STOP AFTER you're all done exercising. Belly weight loss is one of the hardest things to achieve if your goals is to lose fat. However, there are some tricks that you can use to reduce your waistline faster. Stick to them, be persistent and you will be sporting a slimmer figure sooner.