As intensity decreases from extremely high, you shift to the glycolytic system and, eventually, to the oxidative system for moderate- to low-intensity activity. For extremely high-intensity activity, your body uses the phosphagen system. Which system you primarily use depends on your activity intensity. Your body has 3 systems to produce ATP: the phosphagen system, the glycolytic system, and the oxidative system. It is often described as your body’s “energy currency.” Without it, you aren’t able to create or use energy for activity, metabolism, or brain function.
Your body’s energy systemsĪdenosine triphosphate (ATP) is the molecule that allows your body to use and store energy. If you understand these energy systems, you can design your exercise routines to tap the different ways they help your body burn fat. But how your body uses its different energy systems directly relates to how you exercise and maintain your weight. The truth is, the way your body uses energy and burns fat largely depends on the type of exercise and the length of time you exercise. The vast majority of these are marketing myths to get you to buy a product. Many fad exercise programs claim you can “bust fat” in only a few minutes a day or target belly fat to shrink your waistline. You can’t “target” belly fat, but you can lose it. What is the best exercise for fat burning? How do you target “stubborn belly fat”? Can you turn fat into muscle? The short answers are: Over time, almost any exercise burns fat.