Is it best to do cardio on an empty stomach? An hour after eating? First thing in the morning? At the end of the day?
The simple answer is "YES!" Anytime, as long as you're doing it. You will burn fat no matter when you exercise. If you are looking for the maximum possible benefit, then maybe you should consider cardio in the early morning, prior to eating breakfast. In the morning, after not having eaten for several hours, your glycogen is depleted because your body has continued to use it even while you slept. Also, your blood sugar levels are lowered and this creates a great environment for burning fat instead of carbohydrates.
Why does this work? Well, carbohydrates (glycogen) are the body's preferred source of energy (fuel). When this form of energy is running low, your body will resort to other sources of fuel. This means fat! Don't worry, even if you do cardio after eating, you will still burn a combination of fat and carbohydrates. If you can't do cardio in the morning, it is advisable to do cardio after your weight training session. Lifting weights depletes muscle glycogen and can have a similar effect to those early morning sessions.
Also, after an intense cardio session your metabolism stays elevated for several hours. In essence, you keep burning calories at a higher rate for hours after your workout. If you do your cardio close to bedtime, you may not see the same results because your metabolism slows substantially once you fall asleep.
Whatever you do, don't put off eating breakfast until 11 a.m. when you finish your morning workout. Putting off breakfast for half the day will have the reverse effect and slow down your metabolism.
Realistically, is doesn't matter when you do it, as long as you do it. If you aren't a morning person, you may not work out as intensely therefore not see the same benefits as working out later in the day. Get your cardio workouts in whenever it is most convenient for you. Keep them intense and you're sure to see benefits no matter what time of day you do them.
Say It! Mean It! Do It!
