What Does Your Body Burn?

Fat is good.

Your body does need fat because that's what it burns first when you exercise. When you work out, your body will burn fat, then carbohydrates and proteins.

Jeff Gordon writes for the Livestrong.com blog and discusses how your body burns through these things.

After you read through this, it's important to ensure you have these items in your system available to burn, particularly before a prolonged workout. You don't want your body turning to burning muscle as a last resort.