An important question is how or why intermittent fasting helps muscles stay strong, and I think the key factor is the metabolic switch, where the body shifts using ketones as a primary fuel source.

The reason that matters is because ketones are “anti-catabolic” which means they help prevent the breakdown of muscle during fasting. 

They do this by:

 Activating the expression of thousands of genes and proteins throughout the body

 Shifting the source of energy from glycogen in your liver or muscles to your own body fat

This means that your precious muscle is preserved since the body feeds on its own fat for energy. 

Activating Autophagy

An additional way in which fasting helps to preserve and create high-quality muscle is by “activating autophagy”, which is your body’s waste removal system that is present in every cell in your body, including your muscle cells.

So, when you remove the “bad stuff” from your muscle cells, they become:



Not only that, but they will have more energy to power your workouts.

The Power of Ketones

Ketones generate approximately 25% more energy within your muscle cells and every other cell of your body than glucose.

When you have healthier muscles with more energy, your workouts will be better, which means your body will become:



Your body will develop much faster than if you didn’t fast.

The Impact on Aerobic Capacity

Not only that, but recent studies show that intermittent fasting can improve your aerobic capacity (how fast your body can replace oxygen while exercising), which means you will be able to run (bike or swim) longer and faster than before.

If lifting weight is part of your routine, which we highly recommend, you will notice that you recover faster:

 Between sets

 After training sessions

You will also likely be stronger, as the body’s overall/total work capacity has increased. 

Fasting and Growth Hormone Levels

An additional way fasting enhances muscle growth is by increasing growth hormone levels.

This does amazing things for our body including helping our body make new and better-quality muscle after training sessions.

So, Will Fasting Alone Improve Your Muscles?

Yes, to some degree.

But the real benefit comes from when you combine fasting with an exercise program.

The fasting primes the body to get the most out of every workout and also helps your body recover faster, so when you combine:



The benefits of both are amplified.