Written by Stephen Anton PhD on August 3rd, 2020
An important question is how or why intermittent fasting helps muscles stay strong.
I think the fundamental factor is the metabolic switch, where the body shifts to using ketones as a primary fuel source (1).
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 and 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.
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 cleaner and stronger.
Not only that, but they will have more energy to power your workouts.
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 and after training sessions.
You will also likely be stronger, as the body’s overall/total work capacity has increased.
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.
When fasting and exercise are combined, the benefits of both are amplified.