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.

Make sure to check out this blog post with the best tips to optimize your workouts and achieve peak performance.


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.


29 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

      • Christos charalambous Reply

        Για μένα όλλα αυτά ειναι κατανοητά τα μόνα πράγματα που θα ήθελα να ρωτήσω ειναι το εξής:
        1) Εαν θέλω να χάσω λίπος και ταυτόχρονα να αυξήσω την μυική μου μάζα πρέπει να μειώσω της θερμίδες μου και αν ναι ποσο?σε θερμιδες συντήρησης?
        2) της Ημέρες που δέν θα έχω προπόνηση δεν θα κανω Fasting, αλλά πόσο κάτω πρέπει να ειναι οι υδατάθρακες μου? κανονικά της ημέρες που δέν θα έχω fasting δέν πρέπει οι υδατάθρακες να ειναι υψηλότεροι?
        3)Πώς μπορώ να υπολογίσω τα μακροθρεπτικά μου της ημέρες που θα έχω προπόνηση και της ημέρες που δέν θα έχω?

        Ευχαριστώ πολλλυ

        • Jenny M. Reply

          Γεια σου Χρήστο!

          Για να σου δώσουμε συγκεκριμένες συστάσεις για την προσπάθειά σου θα χρειαστούμε περισσότερες πληροφορίες και να εμβαθύνουμε πραγματικά στη σύνθεση του σώματός σου, την προπονητική σου εμπειρία κ.λπ.

          Συν τοις άλλοις, ακόμα και αν γνωρίζουμε κάθε παράμετρο, υπάρχει ακόμα το γεγονός ότι κάθε σώμα ανταποκρίνεται διαφορετικά.

          Παρ’ όλα αυτά, παραθέτουμε ορισμένες συστάσεις που θα οδηγήσουν την πρόοδό σας στο επόμενο επίπεδο:

          1. Αυξήστε την πρόσληψη πρωτεΐνης σε 1,5-2gr/kg σωματικού βάρους

          2. Καταναλώστε τους υδατάνθρακες σας (σε συνδυασμό με τις πρωτεΐνες) κυρίως μετά την προπόνηση με βάρη στην αρχή του διατροφικού σας παραθύρου για να ενισχύσετε τις ορμόνες μυϊκής οικοδόμησης και να επιταχύνετε την αποκατάσταση

          3. Εξαλείψτε τις τροφές που περιέχουν μεγάλη ποσότητα υδατανθράκων τις ημέρες που δεν κάνετε προπόνηση και επικεντρωθείτε στο συνδυασμό πρωτεϊνών & λαχανικών με λίγο λίπος (το ελληνικό ελαιόλαδο είναι εξαιρετικό! Το λατρεύουμε). Αυτό διατηρεί το μεταβολισμό/την καύση λίπους σε εξέλιξη.

          4. Μην το κάνετε πολύ περίπλοκο με το να μετράτε τα μακροχρόνια σας κ.λπ. Επικεντρωθείτε στις συμβουλές 1.-3. και δείτε πώς ανταποκρίνεται το σώμα σας.

          Καλή τύχη! Τα καταφέρνεις!

          Υ.Γ.: Επειδή χρησιμοποιήσαμε έναν διαδικτυακό μεταφραστή, παραθέτουμε ξανά το αρχικό μήνυμα στα αγγλικά για την αποφυγή παρεξηγήσεων:

          Hi Christos!

          In order to give you specific recommendations for your endeavor we would need more information and dig really deep into your body composition, training experience etc.

          On top of it, even if we know every single parameter there is still the fact that every body responds differently.

          Nevertheless here are some recommendations that should take your progress to the next level:

          1. Increase your protein intake to 1,5-2gr/kg bodyweight

          2. Consume your carbs (in combination with proteins) mainly after weight training in the beginning of your eating window to boost muscle building hormones and speed up recovery.

          3. Eliminate foods that contain a big amount of carbs on non-training days and focus on the combination of protein & veggies with some fat (greek olive oil is great! We love it). That keeps your metabolism/fat burning going.

          4. Don’t make it too complicated with counting your macros etc. Focus on tips 1.-3. and see how your body responds.

          Good luck! You got this!

    • 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! 😊

      • Mahdi Reply

        Hi first of all thank you for this amazing article,i have a question,im 20 years old and i weight around 125lbs but i used to weight around 130lbs,how can i gain weight and its been about 2 months that im doing 16/8 fasting and im healthier than ever and im feeling extraordinary

        • Christian Mall Reply

          Hi Mahdi, we’re glad you enjoyed reading this article! If your goal is gaining weight, intermittent fasting might not be the best method to be honest. It’s possible but it’s more difficult to generate a calorie surplus. If you still want to do intermittent fasting, we would recommend choosing a fasting plan with short fasting periods, such as 14-10 😊

  5. sean Reply

    HI, I have read several articles, including this one, all say to lift at the end of the fast. I cannot do that. I have to get up at 5am to work out, then dont eat until 1130ish (work work work). try to have my first meal around 1130-130 depending on work day, then dinner no later than 730.

    I am a retired firefighter so have muscle mass (trying to re-inflate so to speak) but also lose 40LBs from being retired.

    Should i just give in and have a small protein shake after my lifting session? (10min cardio about 30-40min of weights) and give up on the intermittent fasting?

    • Jenny M. Reply

      Hi Sean!

      First of all, it’s important to listen to your body and don’t force things that make you feel uncomfortable. Secondly, it’s not an imperative to work out at the end of your fasting period, it just gives some extra benefits. But being active has so many benefits that you would not want to miss them altogether.

      Would moving your fasting time to having breakfast but skipping dinner instead be something that would work for you?

      In the end, things have to work for you. We can only encourage you to follow your gut and do what you consider the best way for you personally 🙂

      • Mahdi Reply

        Hello, thanks for this amazing article, I can’t train at morning before my first meal so when is the best time for training?

        • Christian Mall Reply

          Hi Mahdi, if you can’t work out at the end of your fasting period, you can also work out during your eating period. If you work out in your fasting period, it generally increases fat burning and is more effective for muscle building, while working out in your eating period brings increased energy availability and allows for higher workout intensity 😊

  6. Norma Reply

    I want to try intermittent fasting and looking at a fasting window from 6pm to 10am. But I also want start a routine and exercise at around 4-5am. I need to lose fat and want to gain muscle. When do you recommend I eat my first meal? And should i take anything pre or post workout?

    • Christian Mall Reply

      Hi Norma, if it’s possible, we would recommend shifting your workout routine towards the end of the fasting period (9 – 10 am). After your workout, we would recommend that you break your fast with a meal that’s high in protein and that contains lots of healthy fats. In order to facilitate gaining muscle, it’s beneficial to give your body some extra protein, e.g., through a protein shake (after your workout, during your eating window). Hopefully, this answers your questions 😊 Happy BodyFasting!

  7. Michelle Reply

    Hi, is it possible for itermittent fasting help me loose weight if i do little to none exercise and sleep all day, since im unemployed im on the coach pretty much 24/7, so can it help a person like me loose weight?

    • Jenny M. Reply

      Hi Michelle!

      Well, let’s put it like this: Intermittent fasting creates favorable hormonal conditions to support weight loss, but it will neither lose the weight for you nor is it a substitute for a healthy lifestyle.

      There are some more factors that comes into play beside the timing of your meals, things like a balanced diet, physical activity, managing stress levels and quality sleep. Intermittent fasting can be a great starting point to embark on a journey to a new me, being the initial spark for building new, healthy habits.

      You might want to give it a try and see for yourself how your body and mind change 🙂

  8. Soni Reply

    I have been fasting with the coach plan for 7 weeks. I have lost 14.4 lbs and just now feeling like it is becoming a routine or habit. I recently started the treadmill just before I break my fast. However, I experience lightheadedness something awful immediately after I complete my 35 minute session. I immediately down about 16oz of water and wait it out, but it is worrisome because it takes about 15-30 minutes to get back to a normal state. What can I do to not feel like I’m gonna pass out after my 35 minute fasting workout? I’m walking at an incline of 3 and a speed of 3mph.

    • Christian Mall Reply

      Hi Soni, it’s always very important to listen to your body and in your case, it seems like your body is overstrained, so we’ll give you some advice which is hopefully helpful for you 😊 One option you could try is shortening your fasting periods and see if your body manages the training periods better then. Another option is keeping the length of the fasting periods but trying a less intense training. A general advice you should always follow is making sure to eat protein-rich and nutrient-rich meals during your fasting periods so that your body is best prepared for the training. And of course, drinking enough is very important as well. However, if you’re still experiencing these issues even after following these tips, we would recommend taking a break from intermittent fasting and consulting your doctor to see if intermittent fasting is really suitable for you. We wish you all the best 🙏

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