Fasted Cardio: Does it Speed Up Fat Burning?

Have you heard that doing cardio before breakfast can actually speed up fat burning? The theory makes sense. If you work out when you don’t have much sugar in your body (like after 8 hours of sleep), your body will naturally turn to fat.

But does it actually work? Let’s examine that.

What Happens in Your Body When You do Fasted Cardio?

Your body basically has 2 main fuel sources that it uses just to stay alive: sugar (AKA glucose) and fat. How much of each you’re burning depends on a number of things. The intensity of exercise matters, and what you eat (or don’t eat) matters.

The higher the intensity of the exercise, the more sugar you burn. The lower the intensity of the exercise, the less sugar you burn.

If you ate a carbohydrate-rich meal within 2–4 hours of your workout, your body will burn more sugar for fuel than if you didn’t have a carbohydrate-rich meal within 2–4 hours of the workout.

So theoretically, if you’re doing cardio before breakfast, you will not have eaten in more than 8 hours, and your body should use more fat for fuel than sugar.

Does it Actually Work?

The theory makes a lot of sense, but can we actually say that specifically because a person was doing fasted cardio they lost body fat faster?

For the most part, people lose body fat at a rate of 1–2 pounds per week. Can I actually say that due to fasted cardio…