Best Time to Do Cardio Exercise

Morning is the best time for Cardio as the carbohydrates are to a minimum at this time.

Another time to perform is after a Weight Training Session as your body has depleted carbs and while cardio will use up body fat for energy. But if you want to do it later in the day just ensure that you do cardio on empty stomach.

The fat burning benefits of doing cardio exercise in a fasted state don’t appear to be anywhere near as significant as most people incorrectly make it out to be. In fact, the more fat you have to lose, the less these benefits exist in the first place.

Which means in many cases, the advantages might not truly be big enough to warrant going out of your way to do these workouts fasted.

At the same time, while this might technically be the best time to do it in terms of weight loss, fasted morning cardio (specifically when done at the moderate to high intensity it usually is) is the worst way to do it in terms of performance (meaning it will be harder for most people if they don’t eat something first) and probably for maintaining muscle while losing fat as well.

Early in the morning before you eat, your levels of muscle and liver glycogen (stored carbohydrates) are low. If you eat dinner at 7 p.m. and you eat breakfast at 7 a.m., that's 12 hours without food. During this 12-hour overnight fast, your levels of glycogen slowly decline to provide glucose for various bodily functions that go on even while you sleep. As a result, you wake up in the morning with depleted glycogen and lower blood sugar - the optimum environment for burning fat instead of carbohydrate. How much more fat you'll burn is uncertain, but some studies have suggested that up to 300% more fat is burned when cardio is done in a fasted, glycogen-depleted state.