Working Fasted: Does It Burn More Fat?

If you are like me (a few months ago) you might not even know what these words mean. Let me start by explaining what fasted state means and why you might want to try exercising when you’re in it.

First, your body is always in one of two states: fasting or feasting. Right after a meal, you are in a feasting state. Your body is getting its energy from the food you just ate. At some point, which is different for everyone, your body uses up all the energy from the food that you’ve eaten. Now you are in a fasted state.

When you are in a fasted state your body has to get its energy from storage since there is no food available. Your body uses glycogen to supply the energy it needs. When the glycogen is used up the body has to use FAT for fuel.

Try Working Out In a Fasted State

If you follow this logic: my body is either using the food I just ate to fuel my workout OR it’s using storage. You can see where this leads. What does my body store?

Glycogen is stored energy or glucose. Your body has to use glycogen for fuel if there is no glucose available. Glycogen is stored in both your muscles and your liver. Once that stored glycogen is used up, your body starts to use fat for fuel.

I feel like I’m repeating myself, and I am. The reason is because I feel like a light bulb has just gone off. This is why some of us exercise for hours upon hours and never lose weight. If your’ goal is to lose weight OR to burn fat, you might stand a better chance if you skip the pre-work out meal.

I would also argue that the scale can be an enemy for many reasons. Eat something salty and you’re two pounds up and that puts you in a bad mood. Don’t use the scale to decide how you feel about yourself. Think about how you are feeling instead.

Are There Benefits to Working Out In A Fasted State?

Yes there can be benefits to working out in a fasted state because your body HAS to use the energy that is stored. Your body can use its fat stores or protein stores. Less fat stored is good because you become more physically fit.

Exercising before you eat hasn’t been shown to increase weight loss from exercise, but it could help you to burn fat.

The other benefit is that your body produces more growth hormone. Your body typically makes growth hormone at night while you sleep, and less of it as you age.

Studies indicate that if you wait to or more hours after your workout to eat, there is a rise in growth hormone. Your body needs growth hormone to maintain, build, and repair tissue in your brain and organs. It can also speed up healing.

What Time Period Is Required to Be In a Fasted State?

The time period that your body needs to get into a fasted state varies. It depends on YOU and what you have feasted on. Generally the time period is 8-12 hours. That means if you finish dinner at 7 pm and workout the next morning at 7 am before breakfast you are probably working out in a fasted state.

Additional Resources

Want to read more about exercising on an empty stomach? Take a look at these articles.

Working Out While Intermittent Fasting

Harvard Article about the benefits of exercising on an empty stomach.