Top Tips to Gain Muscle with Intermittent Fasting


The myth of losing muscle through intermittent fasting is persistent – absolutely unjustified!

Recent studies show that intermittent fasting can even be beneficial for muscle growth. In this blog post you’ll learn which processes are responsible for this and how you can use intermittent fasting as a tool to strengthen your muscles.


Intermittent fasting: building muscle mass or losing it?

Many athletes believe that increasing muscle mass is only possible if you eat several meals spread throughout the day: Otherwise – so the misconception – your body will fall into a catabolic state and your muscles will be weakened due to a lack of nutrients and protein.

In fact, however, our metabolism has adapted over the course of evolution: Muscle mass is thus protected even during periods of starvation, whatever it takes!

It’s true that our bodies break down protein during prolonged fasting (starting from about 16 hours) and use it for energy production. However, this is not muscle protein. Rather, our bodies process defective proteins, e.g. in the skin or intestinal mucosa.

This recycling of broken cell parts (also called autophagy) therefore does not pose a threat to our muscle mass.

On the contrary: Intermittent fasting can even be a great tool to build muscle mass – provided you combine it with the right training and a balanced diet!

The reason for this is the following: During your fasting period, your body does not only switch from glucose metabolism to fat metabolism (ketosis), but also creates the best hormonal conditions for building muscle.

Studies show for example that the production of metabolic hormones (among others adrenalin) increases when fasting up to 180%. The level of growth hormones (especially somatropin) also multiplies. This interaction is the reason why intermittent fasting can preserve or build muscles and at the same time reduce body fat!

In bodybuilding, 16/8 fasting is therefore also called the “Lean Gains Method” and has been used for decades.


How you can successfully gain muscle mass with intermittent fasting

One thing is for sure: Muscles don’t grow from sitting around, of course. Targeted training and a balanced diet are and remain the most important adjusting tools when it comes to gaining muscle.

Nevertheless, you can perfectly support your success in muscle building with intermittent fasting.

Here are the best tips:


1. Prefer working out at the end of your fasting period.

If you work out towards the end of your fasting period, you will also increase fat burning in your body.

Targeted strength training in a fasted state is particularly effective. Also try other kinds of physical activity in order not to exercise too one-sidedly or to overexert yourself.


2. Refrain from extremely long periods of fasting.

The smaller your eating window, the more difficult it will be to get enough nutrients! So it’s best to use fasting in a conscious and sparing way!

16-8, for example, is a good choice. That’s because a meal window of eight hours will leave enough time for adequate nourishment.


3. Take good care of your body.

In addition to having enough water, a nutrient-dense diet is key to healthy muscles. To be specific, this means plenty of vegetables, high-quality protein and healthy fats.

If you want to optimally support muscle growth, make sure to include long-chain carbohydrates (e.g. whole grain pasta or whole grain bread) in your meals on intense training days. This will help your muscles recover. On rest days, a low-carb diet is a great choice.

Also, make sure not to eat too little and give your body enough time to recover.


Intermittent fasting and muscle building – this is how it works

Intermittent fasting does NOT cause your muscles to atrophy.

The opposite is true! When used in the right way, regular fasting periods set the course for achieving maximum muscle growth and fat loss with minimal training effort.

If you work out towards the end of your fasting period, focus on moderate fasting periods, and pay attention to a protein- and nutrient-rich diet, you can significantly increase your fitness with intermittent fasting.


Ready to take your fitness to the next level? Find the optimal fasting plan and delicious, protein-rich recipes for optimal muscle growth in the BodyFast app.


13 thoughts on “Top Tips to Gain Muscle with Intermittent Fasting

    • Christian Mall Reply

      Intermittent fasting can be used to achieve many goals besides losing weight, such as a healthier lifestyle in general or even muscle building. If you don’t want to lose weight, please make sure to not get into a calorie deficit, meaning that you should eat as much calories during the eating period, as you consume during the day. Is there any particular goal you’d like to achieve? Then just let us know and we’ll help you. Please also feel free to contact our support under

    • Christian Mall Reply

      If your goal is to lose inches around your belly, intermittent fasting is a great way to achieve this. Intermittent fasting and sport are a great combination. In order to achieve fat loss and muscle gain in certain parts of the body, targeted strength training is a great support. The BodyFast app helps you find a fasting program that’s best suited for your needs. Happy BodyFasting! 😊

  1. Norma Cherry Reply

    I am 58 yr old female, 5’ 1”, 105 lbs. I have a lot of mid-section body fat regardless of my low weigh, likely due to inactivity for almost 18 months due to foot surgeries) – otherwise I’m active. I’m on my 2nd week of 16-8 fasting (minus weekend) and I’m afraid I might not be getting enough calories as I’m so full early on when consuming my meals (lunch and dinner & no snacking). I feel bloated and can’t seem to finish my already reduced portions. The overly full feeling passes in about an hour but I’m def not hungry. I am drinking a lot of water (143 oz before 5pm just today). Should I reduce the water intake? I’ve only recently started up resistance training. Any suggestions or insight?

    • Christian Mall Reply

      Hi Norma, we would recommend talking to your doctor about your loss of appetite and the bloating. Until then, you should pause intermittent fasting. Regarding your water intake: The BodyFast app can calculate your ideal water intake and we would recommend that you adhere to it. If you are a Coach subscriber, you can also access our SOS feature where you can read an article about stomach issues, such as bloating. We wish you all the best! 😊

  2. Sara Reply

    If I’m exercising towards the end of the fasting period, when is the beat time to eat the first meal? Immediately after the workout? Within 2 hours?

    Thank you,

    • Jenny M. Reply

      Hi Sara!

      It depends a bit on you and how well you tolerate meals after your workout. For many people, a small, protein-rich snack after their workout works best and they then have their meal within two hours after that. In the end, you need to try how this works for you or make according adjustments. The most important thing is that you feel well and not following specific guidelines in case they just don’t work for you 🙂

  3. Ivan De la Rosa Reply

    Hola veo qué recomendais hacer ejercicio hacia el final del periodo de ayuno, En mi caso busco ganar peso, musculo y incluso un Poco De grasa. ¿En mi caso es recommendable hacer ejercicio Al final del ayuno? No me siento con mucha energia en ese momento y mi objetivo no es perder grasa.

    • Christian Mall Reply

      Hola Ivan, es cierto, recomendamos hacer ejercicios al final del periodo de ayuno si quieres ganar músculo con el ayuno intermitente. Si sientes que no tienes suficiente energía en ese momento, te recomendamos que tu última comida antes de empezar el ayuno sea rica en proteínas y fibras. Te deseamos lo mejor en tu viaje de ayuno intermitente! 😊

  4. Daniel Reply


    I’m not new at fasting and this is probably my4thtime on it. I’m doing a long period of fasting and I’m working out at the end of it. I drink a protein milk shake at the end and have dinner 2 hours later. The only problem I’m facing at this moment it’s the water… I’m not a big fan of drinking water and do not feel the need to do it along the day. What do you suggest?

    • Christian Mall Reply

      Hi Daniel, it’s definitely important to drink enough while doing intermittent fasting, especially if your fasting periods are long. If you don’t like drinking water, maybe drinking tea is an option for you? We have a blog article dealing with the best teas for intermittent fasting that you might want to check out: We wish you all the best on your fasting journey! 😊

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