Does Fasting Make You Lose Muscle? The Complete Guide

Fasting, Exercise, and Muscle Gain: A Complete Guide

One big issue people might have with fasting regards muscle gain and loss. When you’re training consistently, you might wonder if intermittent fasting or longer fasts are a good idea. Since you won’t be getting enough proteins to keep your muscle mass, you will lose muscle and won’t be able to gain any?

As long as you keep exercising, you will not lose muscle when you fast. Even when fasting for several days. The way you eat can play an important role in muscle growth, but you don’t need carbohydrates or lots of protein to grow muscle.

As you have already read and heard many things on the subject, you might have built your own opinion on this. So this definitive answer could sound suspicious to you, especially if you have a hard time believing it. Since it’s a really narrow answer to a very big subject, I’ll be tackling all these questions in depth.

The idea of this article is to show you the whole spectrum of muscle gain and how the way you eat (or don’t) affects it.

How do muscle gain and loss work

Difference between strength and muscle mass

First off, there’s something very interesting there, more muscles don’t necessarily mean more strength. Take a look at powerlifters, for example, most of them look strong, but not that muscular, when compared with a bodybuilder for example.

More muscle mass doesn't nessarily mean more strength

When you’re doing anything involving contracting one of the 650 muscles in your body, it comes from a signal triggered by motor neurons. The cell responsible for activating these neurons is called the sarcoplasmic reticulum.

The strength you acquire can simply come from the habit of contracting those muscles and triggering those neurons. In short, the better you get at signaling your muscles to contract, the stronger you can get.

That’s what powerlifters essentially do, they get better at contracting their muscles. That’s also why if you never worked out before and start doing it, you’ll see an impressive improvement in strength at first. You won’t experience much muscle growth, but you’ll be able to lift more weight in no time.

Compare that to the improvement you can get after a year and you’ll see getting stronger and beating those reps, in the long term, will take much more time. This is because at first, you’re training your motor neurons to do a better job at contracting your muscles when they’re not used to it.

You’ll also see in this article that if you can get stronger without much muscle growth, you can also get a lot bigger without gaining much more real muscle cells.

How do muscles grow

The muscles in your body won’t grow when you’re working out, in fact, it’s quite the opposite. Even if you might feel when doing bench press that your chest is expanding, it’s not really. It’s just blood flows flowing to your chest. This feeling is called the “pump” in bodybuilding.

Your muscle will actually grow when you’ll be resting. After a workout, your body will start repairing or replacing damaged muscle fibers. When doing that, it’ll fuses fibers together, which will then form new muscle protein strands. After a while, those fibers increase in numbers and size and create muscle growth.

To summarize, muscle growth, also called muscle hypertrophy, happens when the rate at which muscle protein synthesis occurring is greater than the rate of muscle protein breakdown.

This is a very important part of muscle growth. Keep it in mind, since most theories tend to conclude that muscle breakdown will occur more when fasting (since carbs and proteins can help negate muscle protein breakdown effect), we’ll come back to it later.

The cells responsible for creating more muscle cells, muscle fibers, are the satellite cells, which act kind of like the stem cells for the muscle. Muscle growth will come from the activation of these satellite cells. And that’s where your genetics might come into play.

Not everybody’s satellite cells react the same way, meaning if you’re body is genetically able to respond more to satellite cells, you’ll be able to grow muscle faster. This study conducted on 66 patients over 6 weeks showed that we’re not all created equal when it comes to muscle growth. The percentage of activation of satellite cells directly influenced muscle gain.

That’s why your buddy Jerry looks muscular, with strong shoulders, even though he’s never worked out, while you might be struggling to build any muscle when working out 3 or 4 times a week.

There are three main mechanisms to make muscles grow :

  • Muscle damage: As I already stated, you damage your muscles when working out. This will cause an inflammatory response, which will then activate satellite cells and the repairing and replacing of damaged muscle fibers, thus the formation of new muscle cells.
  • Muscle tension: That’s why when you’re following a workout program, you’ll always try to lift more weight and do more reps. This helps to stress the muscles, which will cause a change in the chemistry of the muscle and activate satellite cells.
  • Metabolic stress: I talked about it briefly before, growing muscle without growing strength. Bodybuilders build a lot of muscle that way, by eating tons of carbs and proteins. This additional glycogen in the muscle will cause swelling around it. The muscle will appear bigger, while not growing muscle cells.

How hormones affect muscle growth

Human Growth Hormone (HGH) and Insulin Growth Factor (IGF-1)

The human growth hormone is released in small blips by the pituitary gland during the day into the bloodstream. HGH half-life is very short, studies showed that the average half-life of HGH in the blood was around 18 minutes.

The direct effects of human growth hormone on muscle growth are not really clear. Some studies suggest that HGH could protect muscles by helping your body mobilize fat for fuel and support the liver in generating necessary glucose.

But the big impact of HGH on muscle comes from its link to the insulin growth factor. HGH doesn’t stick around very long in the bloodstream, that’s because when it reaches the liver it is then transformed into another hormone, IGF-1.

IGF-1 is responsible for regulating the amount of muscle mass growth. It does so by increasing protein synthesis and facilitating the uptake of glucose. It also regulates the uptake of amino acids, which are what proteins are built on, into the muscles. This process also activates satellite cells to promote muscle growth.

Mecho-Growth Factor (MGF)

When talking about muscle growth, testosterone is the first hormone that’ll come to mind.

Testosterone is mostly a man hormone since most of it is produced in the testicles. Women also have some testosterone but in a much smaller amount. Here are some of the many roles of testosterone in the body :

  • Sperm production
  • Libido
  • Beard and body hair production
  • Fat metabolism
  • Bone density
  • Muscle mass

Almost all testosterone is bound in the body and not available for use. When you’re working out, your body will release more testosterone, and it’ll also make the receptors of your muscle cells more sensitive to the hormone. Testosterone can also stimulate human growth hormone, thus helping tissue growth and promoting IGF-1 production.

The main effects of testosterone on the muscle are the inhibiting of protein breakdown, activation of satellite cells and increased protein synthesis.

The importance of sleep

Before I’ll dig deeper into the effect of the way you eat on muscle growth or breakdown, it is very important to note that there are many other factors to these processes. One huge factor being rest and sleep.

As I said earlier, most of the muscle growth that’ll occur will happen during a rested state. Tissue repair and muscle growth occurs mostly during sleep and especially when you’re in REM sleep. Depriving yourself of quality sleep will severely impact the effects of your workouts.

Many studies have found that sleep was directly linked to muscle strength and that, even when working out, not getting enough quality sleep could potentially induce muscle protein breakdown. Muscle loss.

How muscle loss occurs

Muscle loss also referred to as muscle atrophy mostly occurs when your body lacks physical activity. It can come from being bedridden by an injury or disease, aging, nerve damage or plain laziness. So before looking at what you eat that could cause muscle loss, you should look first at the way you exercise.

So you might wonder, if I don’t exercise for a while, I’ll lose muscle. Will these muscles be turned into fat then? That’s a pretty famous misconception. If I simply reverse my previous statement, you’ll get the point:

Muscle loss, also called muscle atrophy, happens when the rate at which muscle protein breakdown occurring is greater than the rate of muscle protein synthesis.

Where does muscle proteins go then? Well, proteins are simply broken down by the body and used or treated as a waste product by the kidney and excreted as nitrogen in your urine.

But this misconception of muscles turning into fat also comes from the fact that your metabolism, with less muscle, will require fewer calories to function. That will not necessarily change your eating habits and the cause you to eat too much compared to what you actually need and thus increasing fat gain.

I already talked in two of my articles about an experiment author Tim Ferris addressed in his book Tools of Titans. He experimented with prolonged fast and on the first 7 days fast, claim to have lost 6 kg of muscle mass.

You might think fasting will make you lose muscle far more quickly than not working out, but that’s the thing, on this fast Ferris was in a hospital, in bed most of the day, and wasn’t allowed to exercise.

Fast-forward to a 10 day fast he did later without clinical supervision and while keeping is exercise routine: he didn’t lose a gram of muscle.

In my previous articles, when mentioning these experiments, I stated that it’s important to keep exercising when fasting. But that’s not the point. Fasting doesn’t have much to do with this, if you want to keep muscles, you have to keep some kind of exercise routine.

But I’m not saying the way you eat have no effects on muscle loss, as you’ll see.

Low-calorie diets and muscle loss

In the many articles I read about muscle atrophy, I realized they often stated that one of the big factors in muscle loss could be starvation. You must know this misconception that if you’re fasting, you’re actually putting your body in “starvation mode”.

Fasting is not putting your body into a state of starvation, you’re training it to use your fat as fuel, so it has all the energy it needs.

I’m not going to talk about the dramatic effects of real starvation people are experiencing in many countries. What I’m talking about is the choice many make, a dietary choice, of putting yourself in some kind of starving state.

And implementing a low-calorie diet actually is pretty close to starving your body. Here’s a definition by Healthline :

What people generally refer to as “starvation mode” (and sometimes “metabolic damage”) is your body’s natural response to long-term calorie restriction. It involves the body responding to reduced calorie intake by reducing calorie expenditure to maintain energy balance and prevent starvation.


What happens when you’re limiting energy intake for your body to like 70% of what it should, is that you’ll effectively put it in starvation mode. You’re giving it food and nutrients throughout the day, but not enough to fulfill its needs.

How fasting and keto affect sleep and energy?

In this unnatural state, the body is going to try and limit energy expenditure. Since you’re only getting 3/4 of the actual energy your body needs to function, your metabolism will go down and do everything it can to burn fewer calories.

That’s this slow metabolism side effect that boomerangs when you go back to eating normally after the calorie restriction diet “worked”.

Congratulations, after a year of feeling tired, cold, hungry and shitty, you lost weight but totally disrupted your basal metabolism. You’ll now regain all the weight and then some, because you’re metabolism is now unable to function properly.

Sorry about that, I can’t stand that stupid low-calory diet theory, this “eat less, move more, dummy” everybody’s been throwing around as the magical diet which never worked for anybody!

But back to muscles, when your metabolism goes down, it’s to preserve energy. One of the main goals of the body is to be able to function with the amount of energy you’re going to give it. Do you know what takes up a lot of energy in the body? Muscles.

So putting your body in this state of starvation is a sure way to lose weight, yes, but at first, most of the weight might come from losing muscles. Muscle breakdown, in that case, will occur in order to limit energy expenditure. This study even concluded that coupling exercise with a low-calorie diet is not even a conclusive way to preserve lean body mass.

How fasting affects muscle mass

Some history

Before diving into the effects of fasting on muscle, I would like to give some history about us humans. More precisely about the original human being.

There are lots of big statements in this article, some myth debunking, and you might think I’m full of it. If most of what we all learned about muscles, diets, and fasting is wrong in some way, what are we left with?

What really helped me understand and accept those concepts, in the beginning, came down to simple logic. Our body might very well be the most complicated and intricate piece of machinery on earth. Yet, we keep thinking it’s a stupid and illogic one.

The body we inhabit today comes from millions of years of evolutions, it learned to adapt to survive. 99.9% of our evolution was done as hunter-gatherers. The original human being hunts for food, picks berries and fights bears. He’s not eating three times a day, counting calories, exercising 30 minutes in the morning, stressed about his job, etc.

We live in a pretty unnatural way for our body and it’s able to adapt through habit making, but it’s not made to be “used” this way.

Imagine the situation, you are a caveman or woman, it’s wintertime, there isn’t much food around. What do you think you’re body is going to do? Limit energy expenditure, leaving you tired, cold and unable to go look for food? Or simply burn fat storage accumulated, give you the energy you need to stay active and preserve muscle?

Caveman or woman didn't eat 3 times a day, they fasted most of the time
Caveman or woman didn’t eat 3 times a day, they fasted most of the time

That’s the original scenario and it makes so much sense! That’s why we’re amazed by all the benefits of fasting: you feel more energized, it preserves lean mass, autophagy kills toxins and cleanses the gut bacteria, etc.

Not eating for a few days puts stress on your body, it’ll turn to fat as storage and, since it’ll be depleting its own stores of energy, it’ll do its best to keep you sharp and able to go look for some food.

If we’re looking at this original scenario with all these myths in mind, we would never have survived. We don’t eat for several days? The body breakdown its own muscles and puts you in starvation mode, leaving you weak and cold. Eating small amounts five times a day must have been the answer!

It just doesn’t make sense.

I think it’s really important to go back to this original scenario and how our body evolved based on that to understand that the effects of fasting are not “impressive”, they’re simply logical. And that all the myths we’ve been fed to for decades are just stupid and illogical.

Will fasting make you lose muscle

No, it won’t.

What happens when you fast is that when the body will stop relying on glucose from the food you eat. On the first day of a fast, your body will keep burning glucose in the form of sugar stored in the body. But those stores will get depleted very quickly and after a day, you’ll start burning fat.

What about proteins? There still is some protein break down in the body, it’s very low, but it still exists. This study checked urine samples of patients after a three day fast and found reduced urinary nitrogen excretion. During these three days, there was no significant change in those samples.

Meaning during this three day fast some proteins were broken down, but with no change between the first and the last day.

You might think that these contradict my first assertion: if there is protein breakdown, then there is muscle loss. Not exactly, these proteins come from two places :

  • Amino acids in your body that are reincorporated into proteins
  • Muscle breakdown, yes, but this is a normal breakdown that occurs all the time: some muscle proteins are broken down and balanced by new muscle formation

Another study (for which the link doesn’t work anymore sadly), on the effect of a 7 day fast on protein breakdown concluded that this process even slowed by around 25% during the fast.

When you fast you switch your metabolism to use ketone bodies as fuel for the brain and fatty acids as fuel for your body. As I stated, protein breakdown occurs all the time, fasting or no fasting. When you’re not fasting its around 75 grams a day, when fasting, it falls down to around 15 to 20 grams according to this study.

So there is muscle preservation, but also, since you’re not getting protein through food, your body will limit this process. Let’s say you fast for a week, you’ll effectively lose around 100 to 140 grams of proteins. Chances are you’ll make up for it with your first meal.

According to the same study, urea nitrogen exertion goes down drastically when fasting. Your body is not stupid, it’s not burning functional tissue when it can feed on fat stores.

The easiest way to convince you, if you’re not yet convinced, that fasting doesn’t make you lose muscle is to take a look at real-life studies done in the field.

This 2010 study looked at patients who did alternate fasting, meaning they would fast every other day. What they discovered is that from the beginning to the end of the 70 days, lean body mass (bones, muscles, etc.) didn’t change.

Take a look at fat-free mass between day 1 and day 70 – Source

This other study from 2016 did a similar experiment, with alternate-day fasting for 32 weeks. During this study, they compared those doing fasting to another group doing a regular diet, with moderate daily caloric restriction.

While weight loss on both diets was similar, those on the low-calorie diet lost 0.8 kg more lean mass than those fasting. And during this experiment, lean tissue increased by around 0.5% on the regular diet and more than 2.2% when fasting. Meaning fasting could be more than 4 times more efficient at keeping lean tissue.

Another effect of fasting is the increase in counter-regulatory hormones such as adrenaline, noradrenalin, activation of the sympathetic nervous system, cortisol and growth hormone. These hormones are a direct response to insulin levels dropping in the body.

Fasting doesn’t cause your body to shut down contrary to some beliefs, it’s quite the opposite. Adrenaline, noradrenaline, and cortisol are released in the blood in order to keep your body ready for action. These counter-regulatory hormones have an energizing effect on your body.

Resting energy expenditure, the energy used to regulate body heat, by the brain, liver, heart and other organs, increased even after four days of fasting, according to this study. They even found out that energy used by the metabolism increased by around 10% during the fast. Meaning you get more energy when fasting.

The growth hormone is also one of the big counter-regulatory hormones which increase when fasting. The secretion of growth hormone increases by 2 or 3 times on the first day of fasting, up to the fifth day. As I said earlier, growth hormone is linked to cellular growth and, through other hormones, muscle growth.

Increases in growth hormone secretion during fasting – Source

So when you break a fast you’re body will have ramped up growth hormone during this time. Breaking the fast will spike up insulin and, with growth hormone levels being really high, promote protein synthesis and muscle growth.

This process is related to autophagy, your body will not only create new muscle tissue, but it’ll also rebuild necessary proteins and break down unnecessary ones. In short, fasting will help rejuvenate lean tissues.

How to grow muscles when fasting

Misconceptions about growing muscles and nutritions

Your body doesn’t burn fat into muscles

This one as already been addressed in this article since I talked about the physiology of muscle building. But it’s a huge one and I used to think that too: your fat transform itself into muscles when you’re working out.

Of course, if you’re burning fat for energy, some of this energy will be used by the mitochondria to fuel your muscles. But the fat you burn doesn’t transform into muscles, it turns into fatty acids and ketone bodies. Good energy for your body.

But if you follow a regular, eating three times a day diet, you’ll mostly be burning up sugar and depleting your body’s glycogen stores. Building muscle will increase your metabolic rate and your body’s ability to burn calories. That’s great, you just need to train your body to use fat as fuel with fasting and keto to avoid only burning sugar stores.

Carb loading isn’t necessary to build muscle

Little disclaimers, I’m not going against bodybuilders diet, carb-loading like crazy to grow muscles. As I said earlier, carb loading and doing heavy lifting might cause muscle swelling, therefore muscle growth.

You’ll grow the look of your muscles, but not necessarily your muscles cells. So if you want huge muscles, you could definitely look at bodybuilders diet. But if you’re looking to get ripped, meaning growing muscles while keeping lean, that’s not the way to go.

In your whole body, you have around one teaspoon of sugar in your blood. Still, most people consume up to 35 times this amount on a daily basis. Glucose or sugar is not needed by the body, there are no essential carbs. Your liver can break down proteins to make sugar if it needs to.

You might argue that if you want to build muscle, you need to trigger insulin since it’s one of the hormones responsible for muscle growth. But you can spike up insulin without eating a huge amount of carbs and, as we’ll see later, you don’t need insulin when working out, you need some insulin afterward.

Carb loading will make you fat, insulin will, of course, help build muscles, but too much insulin will cause many other ill-effects (insulin resistance, diabetes, obesity, etc.). Keeping carbs to a normal consumption is enough to raise insulin and help you build muscles in a healthy way.

One last thing I wanted to mention about carb-loading: as I said, you will certainly gain fat when doing this, and studies have shown that the more weight you carry, the less anabolic you actually are. This 2016 study concluded that :

These data indicate that impaired postprandial myofibrillar protein synthetic response may be an early defect with increasing fat mass, potentially dependent on altered anabolic signals, that reduces muscle sensitivity to food ingestion.


Meaning more fat mass equals less, or altered, anabolic signals. The leaner you are, the more proteins will go to your muscles after ingestion. More fat will also increase a specific protein in the body (called TNF-alpha), which could be responsible for slowing muscle growth.

You don’t need all these proteins to grow muscles

When I started exercising every day, I contemplated the idea of getting protein shakers. After all, nutrition plays a big role in muscle growth and proteins are key, right?

Proteins are key, that’s right, but you don’t need to consume nearly as many proteins to grow muscle. The body is incredibly efficient with proteins, it recycles them so it doesn’t need a lot.

So the average 3 to 6 ounces of protein a meal is enough. When taking a look at urine samples of patients loading with proteins, researchers found that nitrogens amount (used to measures protein wastes) was really high. Meaning most of these good proteins ended up in the toilets.

And getting too many proteins can be bad for your body for two reasons:

  1. Through gluconeogenesis (new glucose making) excess proteins will be converted into sugar in the liver, then used as energy or stored as adipose tissue. Fat for short.
  2. Processing lots of proteins throughout the day can put a strain on your kidneys and cause problems. You might have heard of the high-protein Dukan diet that was famous some years ago and the many articles about it promoting kidney stones and other renal diseases.

To summarize, you need proteins to build muscle, but your body is very efficient with it and you don’t need nearly as much as you think. Getting good, healthy proteins in regular amounts is enough even if you plan on building muscle.

And to conclude with yet one more advantage of fasting: as a side effect of fasting, the elevation in the human growth hormone will help spare proteins in your body.

When should you workout

I’ve read many things on the subject, but one thing that always comes up is that you should try working out when fasted. If you do intermittent fasting for 16 to 18 hours, exercise during this fasting window.

If you’re experimenting with intermittent fasting you might already have discovered that. Exercising is way easier on an empty stomach. But physiologically, there are great benefits to this :

  • When fasting, you’re actually stressing your body, producing more adrenaline and epinephrine, which are muscles sparing
  • It also increases hormone-sensitive lipase, but this takes generally several days of fasting to really kick in. HSL main role is to mobilize fatty acids in fat stores, thus helping burn more fat and signals the body to preserve muscle
  • I also read that fasting contracts blood vessels in a very specific way, increasing blood flow, especially to bigger muscles like quads, chest, glutes, and back

I didn’t yet talk about an anabolic signal in your body called mTOR (mammalian Target Of Rapamycin), which is responsible for both extra and intracellular signals and is a central regulator of cell proliferation, survival, and growth.

mTOR has been found to be a key regulator in maintaining muscle mass. When mTOR is activated, it will increase protein synthesis. But mTOR works alongside with insulin, meaning the more insulin, the more mTOR. So you would need to spike insulin levels in order to activate mTOR and protein synthesis.

You might think that, logically, you should eat before working out. Spiking up insulin so that when working out, mTOR does its work as it should and increase muscle building.

But protein synthesis will occur up to 24 hours after a workout. As I said earlier, muscle growth happens when the body is resting, not during the workout. So you don’t need to increase mTOR and insulin levels during the workout.

When you’re constantly eating and getting lots of carbs, your body will become insulin resistant and your cells won’t react the way they should when combined with insulin. Leading to type 2 diabetes and other health problems.

If you’re fasting, you’re actually reversing that. Throughout the day, insulin sensitivity will build, and your body will be extra-sensitive to any food you eat, spiking up insulin when it happens. Moreover, exercise has been found to increase insulin sensitivity too!

So to summarize, after a 16 to 18 hours fasting, you’re body will be really sensitive to insulin. If you work out right before the end of your fast, you’ll be increasing this sensitivity even more. And after the workout, when you’ll be breaking the fast, you’ll actually have an insulin spike and which will activate mTOR and promote protein synthesis.

As I said earlier, muscle growth will happen for around 24 hours after working out, so you don’t necessarily need to eat right after working out. But this way, you’ll be eating when insulin sensitivity will be the highest in your body.

Think of it this way: the important is not so much to break your fast right after working out, it’s more to workout at the very end of your fast. Both are the same, but this way you really get my point.

What should you break your fast with

If you’re really aiming for muscle growth, what you’ll break your fast with will have an impact on how much progress you’ll make. I don’t think it’s rocket science either and that you should be really strict about it.

I’ll talk about scientific stuff, but again, don’t obsess over it. As long as you’re getting a healthy meal with enough proteins, it’s a really good start.

Breaking a fast after a workout with carbs


This one depends on whether you’re doing keto diet or not, but eating some carbs for muscle growth, in this specific situation, can really help. Since the idea of the meal is to spike up insulin levels, getting some carbs will definitely help with that.

You should privilege good carbs if you can of course, like brown rice, quinoa, oats, potatoes, seeds, nuts, lentils, kidney beans, etc. You could also get some fruit to add fructose to the mix.

We have different ways of transporting glucose inside the body, glucose will use a transporter called sglut1. So when you get glucose, through brown rice, for example, each molecule will be transported through slgut1. But your body’s ability to transport glucose is limited by the amount of sglut1 transporter. This means some of the glucose could be left unused or just sitting in your blood sugar.

Fructose takes a different transporter molecule, called glut5. Combining fructose and glucose can potentially double carbs absorption, helping get every bit of it to be used for your body tissues.

On a side note, glucose needs sodium to be properly absorbed, through the sodium gated channel. The aforementioned sglut1 being a sodium-dependent transporter. So don’t forget to add salt, preferably good quality salt, to the mix.

Breaking a fast after a workout with lean proteins


Of course, you should get good lean proteins when breaking your fast. That’s common sense! Those proteins will be used for synthesizing muscles. But again, it’s not advised to get too many proteins, if you don’t want it to end up in the toilets.

Another effect of proteins is that it will help increase mTOR signaling in the body through certain amino acids found in proteins. This study shows how protein synthesis is regulated by essential amino acids and how this affects mTOR.

Breaking a fast after a workout with good fats


You can add good fat to the mix, especially omega 3s which, according to this study, can also help improve protein synthesis for up to 50%. Omega 3s when spiking up insulin won’t result in much of fat intake, plus it’ll actually open fat doorway and help good carbs and proteins get through.

On a side-note, I also read elsewhere that omega 3 also has powerful anti-inflammatory properties. Since muscle growth comes from some kind of inflammation in the body, this could potentially reduce inflammation in the muscles, thus muscle growth.

Again, that’s a lot of conjecture, so don’t freak out about it!

Should you supplement and how

As we learned, getting protein shakes is not a necessity to build muscle and this could lead to good proteins ending up down the drain. What I’m going to advise you to get is a pre-workout. The idea is to get you pumped up, energized, giving you more endurance and preventing muscle fatigue, before working out.

Since working out at the end of a fast is the best way to promote muscle growth, this means that your pre-workout should be sure not to break your fast. And especially not spike up insulin, since it’s important to do that after exercising.

This means that 99% of the pre-workouts you can buy cannot be used without risking to break a fast. You’ll have to create the mix yourself. But don’t worry, I’ll give you the ingredients you’ll need and why, as well as a fast-safe pre-workout recipe!

No Branch-Chained Amino Acids or BCAA

One of the most common components of pre-workouts is BCAA, for Branch-Chained Amino Acids. And BCAA’s contain an amino acid called Leucine, which will trigger an insulin response.

I’m not advising you against BCAA, they’re great supplements and fine for working out. They are known to :

Among other things. So it totally makes sense that pre-workouts would be using BCAA in their recipe, they’re great and if you’re already supplementing with them, good for you!

But if you’re looking to alleviate the effects of fasting on your body, you shouldn’t use them when fasted.


Beta-Alanine from BioTech USA I use in my pre-workouts
The Beta-Alanine, from BioTech USA, I use for my pre-workouts

Bata-Alanine is a non-essential amino acid. Its function is not to synthesis protein, unlike other amino acids, it’s more of a performance enhancer.

Coupled with another amino-acid called histidine, beta-alanine will produce carnosine. Carnosine is stored in the muscle and its main goal is to reduce the acidity in the muscle.

When you’re exercising, your muscles will burn glucose for energy, through this process called glycolysis. When broken down, glucose will turn into lactic acid. The more acidic your muscles get the less glucose gets broken down, the less energy they’ll get.

On the contrary, the more carnosine in the muscle, the more energy, and endurance.

Supplementing with beta-alanine shown that it increased carnosine levels by up to a staggering 80%, leading to better athletic performances.


Citrulline from BioTech USA I use in my pre-workouts
I use BioTech USA again to supplement with Citrulline

Yet another non-essential amino-acid, citrulline is also not used for protein-synthesizing. One of the things citrulline does is converting to arginine in the body. You might wonder why not take arginine directly?

Well arginine by itself doesn’t last very long in the body, while citrulline will not break down, but convert into arginine. Studies showed that consuming citrulline is more effective than arginine directly.

What will happen when gett citrulline, and ultimately arginine, is that it will widen your arteries and vein. This is also called vasodilatation and it can improve blood flow to your blood pressure and tissues.

It’s been found to help improve oxygen content and usage in the muscle, which is great for cardio and endurance, as well as increasing weight lifting performance. This study got an impressive 53% improvement in repetitions when training supplemented with citrulline and 40% less muscle soreness in the two days following the workout.

Good salt

Pink Himalayan salt from Nutrisslim I use for my pre-workouts

I mentioned the importance of salt in many of my articles and almost every time I’m going to advise you to look for good salt. Not simple table salt, which could leave you bloated, but real sodium-packed salt. Pink Himalayan Salt is one of the best.

Why exactly should add salt to your pre-workout? Well, it can potentially improve blood flow in your body. What will happened when you start exercising is that you’ll lose water. That’s the very first thing your body does.

Your body’s metabolism, when working out, will need a higher volume of blood in order to deliver oxygen and nutrients to the working cells as effectively as possible. The less blood volume, the harder it is for your heart to get those to your muscles, meaning your heart rate goes up and performances will go down.

Salt will naturally draw and keep water in the body. It’ll also help keep water inside the muscles, helping muscle contraction from a physical standpoint.


Now you might wonder how to mix all these ingredients? Well if you’re used to fasting you should already know what’s the best companion to a fast: coffee.

Coffee, aside from tasting really good, contains caffeine which has added benefits when it comes to exercising. It can :

Caffeine will also leave you more energized and you’ll get a rush of dopamine when drinking it. Yes, that’s what makes it highly addictive, but that’s also a great way to boost morale, motivation and overall energy.

A fast-free pre-workout recipe

My fast-free pre-workout recipe

As a disclaimer, I’ll be vague about the amount for each ingredient. Start with a regular cup of coffee you would use and play with them. Try with maybe fewer hundred milligrams for each amino acid and see how that improves your workouts. You can always increase these amounts later.

Regarding salt, that’s entirely up to your taste, the idea is still to be able to drink it, so don’t overdo it, use what amount you can stand.

Concerning coffee, you can either get a cold brew or warm coffee, but it’ll be harder to mix the ingredients in a cold liquid. I always take it in a warm coffee, but I think I might change that to cold brew in the following weeks. The mix is salty and acidic and it doesn’t taste good. You could always put the mix in a bigger coffee to soften the taste.


  • Around 500 milligrams of citrulline powder
  • 500 to 1000 milligrams of beta-alanine powder
  • A pinch of good sodium-packed salt
  • A cup of coffee (around 8 oz / 2.5 dl)

Simply pour yourself a cup of joe, add in the mentioned ingredients and stir well. You can also mix all this in a blender but that’s not a necessity.

Drink it around 30 to 45 minutes before working out. What I usually do is that I wait for the tingling you will get from the beta-alanine, you might not experience it, but with around 500 to 800 milligrams every day, I definitely do. It’ll tingle the tip of your fingers, the back of your neck and your forehead. At least that’s how it works for me.

But along with the tingle, you should feel pretty hijacked from the mix and, you might not realize it the first time you workout, but you should be able to perform better. I personally feel more focused and energized, even though the exercises don’t seem easier.

You should see results in the number of reps you’ll be able to do without even realizing it at first. At least, that’s what happened to me consistently when I started using this pre-workout.

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