The Truth About Fasted Cardio and How Fat Loss Works

Does Fasted Cardio Actually Burn More Fat?

Still stuck in the 90’s doing fasted cardio? You aren’t alone.

First off, there is a time and a place for fasted cardio and it is a principle that I use regularly. Many people misunderstand the concept of fasted cardio and therefor misuse it. Here is what you need to know.

Fasted cardio is when you perform longer cardiovascular exercise after not eating for 6+ hours. This is done with the hopes that somehow because you don’t have food in your stomach, that magically your body will burn body fat instead. Not necessarily true.

Here is how it works. You have 3 sources of energy…

1. Sugar in your bloodstream. This comes from the food that you eat. So when you eat a piece of candy, it gets absorbed from your stomach into the bloodstream to be used as an immediate energy source.

2. Glycogen from the liver. This is your “reserve tank” of energy. When the sugar in your blood runs out, you tap into the liver for more energy. This extra “gas tank” can only hold so much, and when it overflows with glycogen, the leftover gets converted as fat.

3. Bodyfat. If you run out of the above two sources, you tap into your body fat for additional energy. You will convert the fat on your body into energy to be used for exertion.

Back to fasted cardio. The benefit of fasted cardio isn’t that it somehow specifically burns fat off of your body, it’s that it often times (but not always) puts you in a caloric deficit. The caloric deficit is what makes you burn fat, not the fasted cardio.

So in reality, fasted cardio does not burn fat more than it would if you did cardio on a full stomach. It’s just that if you choose to do fasted cardio, the result is that you will likely be in a caloric deficit because you are fasted.

I discuss this in more detail in the video below.