Momentum in the Mountains 2024


Intermittent Fasting Exercise and Stored Sugar

author avatar Dr. Eric Berg 06/10/2024

Prepare to turbocharge your health and fitness progress by pairing fasting with exercise. This potent combo can help you achieve your goals faster, and with greater ease, by strategically aligning your workouts with periods of fasting.

Despite its long history, fasting has only recently received due attention from the scientific community. The payoffs are enormous: burn fat, sculpt lean muscle, and rediscover your zest for life – all made possible when you team up fasting with a consistent exercise routine.

Ever wonder how fasting and exercise can supercharge your fitness goals? We're about to reveal the fascinating science behind this potent combination, demystify the different approaches, and offer practical tips to help you achieve your ideal physique.

The Science Behind Fasting and Exercise

Fasting and exercise are a powerful combination for getting healthy and fit. When you fast, your body kicks into high gear, making exercise even more effective. Let's look at how fasting and exercise team up to deliver amazing benefits, starting with what happens to your glycogen reserves.

How Fasting Induces Beneficial Stress Responses

The moderate stress of fasting triggers a natural response in your cells, making them stronger and more resistant to damage. This phenomenon, known as hormesis, is akin to how your body responds to exercise - by becoming more resilient and efficient.

When you fast, your body undergoes a profound shift. Inflammation dwindles, oxidative stress wanes, and your body becomes more resilient to stress and disease.

This hardwired response is facilitated by a triumvirate of molecular pathways: AMPK, sirtuins, and NRF2, which kick in during fasting.

Optimizing Fat Burning Through Fasting and Exercise

Fasting and exercise team up to create the ultimate fat-burning duo. By forcing your body to rely on its stored energy, you can switch into fat-burning mode faster, burning more fat and revealing the lean, toned body composition you've been working towards.

The Role of Glycogen Reserves in Fasting

Glycogen is the body's primary storage form of carbohydrates, found mainly in the liver and muscles. When you fast, your body uses up its glycogen reserves before burning fat for fuel.

The length of your fast and your activity level determine how quickly your glycogen stores are depleted. During a short fast of 12-16 hours, your liver glycogen is significantly reduced, but your muscle glycogen remains relatively intact.

As you extend your fast beyond 16 hours, your body starts to break down more fat for energy while preserving muscle glycogen for essential functions. This is where the real fasting exercise benefits kick in, as your body taps into its stored fat for fuel.

Choosing the Right Exercise Intensity for Fasted Workouts

When exercising in a fasted state, it's essential to choose the right intensity to optimize fat burning and minimize potential performance drops. Low-to-moderate intensity exercises like walking, jogging, or cycling are ideal for fasted workouts.

These activities primarily rely on fat for fuel and can be sustained longer without depleting glycogen stores too quickly. Intensity is vital when it comes to fasted workouts, and exercises like sprinting and weightlifting require a lot of energy.

At first, you might struggle to keep up the pace, but as your body adapts and becomes more efficient at burning fat, you'll be able to increase the intensity and see greater fat loss and improvements in body composition.

Navigating the Adaptation Phase

When you start incorporating fasting and exercise into your routine, you may experience some initial challenges as your body adapts to this new way of fueling itself.

This adaptation phase can last anywhere from a few days to a few weeks, depending on your individual metabolism and fitness level.

Symptoms of Incomplete Adaptation to Fat Burning

Your body is radically shifting, and it's normal to feel growing pains. You might experience fatigue, headaches, low energy, or notice fluctuating blood sugar levels. The key is to listen to your body and respond by tweaking your fasting and exercise routine.

To manage these symptoms, you can gradually increase the length of your fasts and the intensity of your workouts over time.

Make sure to stay hydrated, get enough sleep, and consume nutrient-dense foods during your eating windows to support your body's adaptation process. This will help you stay on track with your weight loss journey and reach your goals.

Intermittent fasting plate concept

Maximizing the Benefits of Fasting with Healthy Ketosis

What happens when you pair fasting with exercise? You create a perfect storm for achieving healthy ketosis.

In this state, your body undergoes a radical transformation, effortlessly burning fat for fuel and generating ketones – a crystal-clean energy source that fires up your brain, soothes inflammation, and revitalizes your overall well-being.

Ready to turn your body into a fat-burning machine? Ditch the carbs and bring on the healthy fats. This subtle diet shift can help your body adapt to using fat as its primary energy source – ketosis.

To supercharge this process, incorporate intermittent fasting and time-restricted feeding into your daily routine. Exercise and fasting have been a powerful combo for me.

By tapping into my body's natural ability to burn fat and produce ketones, I've experienced a significant boost in energy, clearer thinking, and an overall sense of well-being.

Incorporating bone broth into this routine has further enhanced these benefits, as the bone broth benefits include providing essential nutrients, supporting joint health, and aiding digestion.

If you want to level up your health, try this dynamic duo and experience the transformative power for yourself.


Fasting exercise benefits are real, and they can profoundly impact your health and fitness journey. By strategically combining periods of fasting with regular exercise, you can burn fat, build muscle, and improve your overall health and well-being.

Fasting and exercise are essential, but they're just two aspects of a much larger picture. To achieve real success, you need to adopt a holistic approach that combines healthy habits, regular physical activity, and restorative rest – the result will be a firmer, healthier you.

So, if you're ready to improve your fitness, consider incorporating fasting and exercise into your routine. Start small, listen to your body, and be patient with yourself as you adapt to this new way of life.

With time and consistency, you'll start to see and feel the benefits of fasting exercise, and you'll be well on your way to achieving your health and fitness goals.

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