The Ketogenic Diet and Strength Sports

A well-known misconception among strength athletes is that carbohydrates are an absolute MUST to be able to grow muscles and to form a well-formed and muscular body. However, this is not true.

It is just one of the many misconceptions that exist around the ketogenic diet and sport . 

The ketogenic diet goes well with strength sports, and in this article we will explore the possibilities of the ketogenic diet in combination with one specific branch of sport, namely strength training and bodybuilding.

The key to a well-defined and muscular body is to follow five important principles:

  1. Train well . Your muscles need to be stimulated in a certain way so that they start to grow.
  2. Eat enough protein . If you want your muscles to grow and recover, you will have to provide them with the building blocks that make this possible. Proteins provide your body with these essential building blocks.
  3. Eat the right amount of calories . Depending on your goals, whether you want to lose fat or increase your muscle mass, it is important to consume the right amount of calories. In the ketogenic diet you can influence this by increasing or decreasing your fat consumption.
  4. Keep an eye on your hormones . Strength training, good nutrition, essential fatty acids (such as omega-3), and a good sleep pattern are all factors that play a role in maintaining and achieving a good testosterone and growth hormone balance. Factors such as stress (due to a lack of sleep, for example) can promote muscle breakdown.
  5. Drink enough water . And with enough water we mean plenty of water. You will lose a lot of water and electrolytes during the ketogenic diet and during exercise. It is extremely important to supplement this well.

In this article we will discuss the above principles point by point. Do you want to quickly find a topic in this text? Click on one of the topics above. 

Train well.

Train well. That is of course a fairly cryptic and general tip. Of course you have to train well, but the question is:

What makes training good? 

Good training means that you give the right stimuli to your muscles so that your body is stimulated at cell level to make adjustments.

The human body is by far the most wonderful machine in the world. It has so many special features when it comes to intelligence and power .

What makes man, and therefore the human body, the most special is perhaps the incredible adaptability to be able to withstand all the obstacles of daily life.

But the body doesn’t just change. Under normal circumstances, the body tries to maintain a stable state. A physical status quo. It is a kind of physical comfort zone that is also called homeostasis .

Only when you expose your body to certain types of stress that disrupt this homeostasis, will the body give an adaptive response. For example, if you get a splinter in your finger, your body reacts with an inflammatory response to “swear out the splinter.”

The purpose of the inflammatory response is therefore to restore homeostasis.

Muscle growth works the same way . When you give stress to your muscles through strength training, you disrupt the homeostasis of your muscle cells. The reaction that your body gives is that it wants to strengthen the muscles, so that it WILL be able to withstand the stress of exercising with a certain weight next time .

An example:

Suppose you can print 21 times in succession. In which you have to push the last 3 times, you really have to do your best to be able to raise yourself.

The first 18 prints were within the physical comfort zone of your body. It is these last 3 repetitions that put extra stress on your muscles, which disrupts homeostasis in your muscle groups (chest muscles and arm muscles in this case).

Because your body wants to prevent this disruption of homeostasis in the future, it will trigger a mechanism that makes your chest muscles and arm muscles stronger.

The result is that as you push more often, your muscles become stronger and stronger. The result is that you get more muscle mass and become stronger.

If you want to train well, then you must ensure that you continue to stimulate your body in the right way and you will continue to disrupt the homeostasis of your muscle groups to make progress.

In his book The MAX Muscle Plan , Brad Schoenfeld (an international body composition and training authority) describes how you can disrupt this homeostasis in various ways by manipulating certain aspects of your training :

  1. Intensity
  2. Volume
  3. Rest intervals
  4. Tempo
  5. Training frequency
  6. Exercise selection

Let’s discuss them piece by piece.


Training intensity is perhaps the most important aspect of training that you can manipulate to stimulate muscle growth. Intensity in this case refers to the weight of the weight with which you perform exercises.

Suppose you can bench press 8 x 60 pounds. By increasing the intensity and using extra weight, you can get your muscles out of their comfort zone. So you can try to bench press 8 x 65 kilos.


Volume refers to the number of repetitions that you can perform with a certain exercise with a certain resistance . To use the example of bench press again:

Suppose you can bench press 8 x 60 pounds. You can then increase the volume by trying to bench press 10 x 60 kilos. These two extra repetitions can ensure that you cause enough extra stress with your chest muscles, a correct stimulus that causes muscle growth.

Rest intervals

This is also an important way to influence your training. You can make the rest that you take between exercises shorter, so that your muscles have less time to recover during exercises.

If you train at a high intensity (so with heavy weights) then it is advisable, for example, to take a longer break between exercises. With a lighter intensity, it is advisable to take fewer breaks.


Tempo is also a very interesting way to influence the weight of your training. You can adjust the tempo at three moments during an exercise with weights. During one repeat of squats, for example, there are three types of muscle contractions:

  1. Concentric (or positive) contraction of the muscle , moving the weight against gravity. With squats this means the part of the repetition where you push the bar up.
  2. Eccentric (or negative) contraction of the muscle , where you let the weight move with the force of gravity. With squats, this means the part of the repetition where you lower the bar.

  3. Isometric contraction is the moment when the weight is not moving. With bench pressing, this is therefore at the end of the concentric contraction (legs stretched with rod resting in the neck) and at the end of the eccentric contraction (in lowered position).

The advice for strength training is to execute the concentric part of the movement in an explosive way, and the eccentric part of the repetition more slowly.

The eccentric movement of a repetition causes muscles to stretch. This tendency in the muscles causes a lot of stress for the muscle tissue. If you then perform this part of the repetition slowly, the muscles must withstand this stress for longer.

More stress for the muscles means that the body will create more muscle mass to be able to resist this stress next time.

Training frequency

This refers to the number of times you train during a certain period.

If you only train once a week, then you are probably not using the potential of your muscles to grow.

At the same time, it is also not desirable to train certain muscle groups too often, because this way you disrupt the muscle recovery process.

The rule of thumb:

Maintain a minimum of 48 hours of rest between training the same muscle group.

This 48 hours is based on the period in which protein synthesis takes place. This process is needed to restore muscles and therefore to make them stronger.

Exercise selection

The alternating exercises is essential for promoting muscle growth.

To achieve complete, balanced development of your muscle groups you must vary with exercises so that you put muscles to work from different angles and movements.

By alternating exercises you ‘surprise’ your muscles and they are put to work and stimulated in other ways. You create effective stimuli, and effective stimuli of the muscles ensure muscle development.

How to train well during the ketogenic diet

A well-known phenomenon when you have just started the ketogenic diet is that your body still has to adapt to the use of fat as a fuel, and that during this adjustment period you may not be able to train as hard as you are used to.

This is because your body can no longer draw on the usual source of fuel (sugars). It therefore means that the energy supply of the muscles is temporarily disrupted during the period that the body switches from glycolysis (glucose as fuel) to ketose (fat as fuel).

To understand what effect this has on your sporting performance, it is important to look at cell level how your cells burn energy.

There are three primary energy systems that use your cells as fuel to get you moving:

  • The phosphagen system
  • The glycolic system
  • The aerobic system

We will explain these fancy scientific terms in understandable language so that you understand how it is possible that in the initial phase you may not be as strong as a ketogenic diet as usual.

Phosphagen system

The phosphagenic system is a special mechanism that does not consume any fat or carbohydrates. The substance that plays a key role in this is called adenosine phosphate (ATP).

It is an energy molecule that can be obtained from stored creatine phosphate in the muscle cells. This ensures that your muscles can get energy very quickly, faster than with any other energy system.

Unfortunately, humans can only build up a very limited stock of ATP. A person carries around 50 grams .

ATP can therefore only provide the body with energy for a very short time and it is seen as the primary energy system for short and explosive efforts, such as short sprint sessions and heavy exercises with weights (1 to 5 repetitions with heavy weights).

That is why fatigue strikes very quickly with such efforts.

Glycolic system

When the phosphagenic system with the ATP is exhausted, the body switches over to glycolysis , whereby glucose is used as a fuel.

This glucose is obtained from the sugar currently circulating in the bloodstream, or from stored glycogen in the muscles and liver.

This system in which glucose is burned in the muscles remains active during efforts that last between 30 seconds to two minutes . For example, think of a 400 meter sprint or weight exercises of 10 to 20 repetitions.

Aerobic system

The aerobic system starts working when the muscles cannot generate enough energy without the help of oxygen.

The aerobic system can produce ATP from fat, carbohydrates and sometimes also proteins. This makes it able to make a lot of ATP, more than other energy systems. However, it is also the slowest system.

You could compare the aerobic system with a large slower tour bus equipped with a huge diesel tank that can take you far beyond the national borders. The glycolitic system is a fast sports car that unfortunately can only come to a neighboring village. The phosphagen system is like a rocket , but one that runs out of fuel after 10 seconds!

The effect of ketosis on your training

Now that you have read that the glycolic system uses sugar from your blood and from glycogen to make sporting efforts possible for 30 seconds to 2 minutes, it makes sense that during the initial phase of your ketogenic diet you will have more difficulty with these exercises.

After all, your body will have far fewer sugars available to use this system.

If you want to prevent loss of strength and muscle loss during the adjustment period, during which your body makes the transition from glycolysis to ketosis, it is advisable to train in the ‘domain of the phosphagen system’ during your exercise session.

This means that you make your sessions short but powerful . With weight exercises you limit yourself to a maximum of 5 repetitions.

So even when you are in the transition phase from a carbohydrate-rich diet to a low-carbohydrate diet, you can still grow muscle mass.

Brad Schoenfeld, the aforementioned expert in the field of muscle growth, has determined from research that a training with short sets (max 3 repetitions) can produce the  same results in the field of muscle growth as longer sets of 10 repetitions. The most important thing is that the total volume (repetitions x weight) is comparable.

Let us take the example of bench press. Suppose you normally bench presses 4 sets of 10 repetitions, weighing 70 kilos. This means a total of 40 repetitions times 70 kilos, which amounts to a total volume of 2800 kilos.

The above calculation example therefore falls in the domain of the glycolitic system. If you want to keep it within the domain of the phosphagen system, you will be able to train harder and shorter sets.

If you want to achieve a total of 2800 in sets of 4 repetitions, you can, for example, bench press 7 sets of 4 x 100 kilos. As we have previously read in this article, it is important to get more rest between sets, because the weights are heavier.

The disadvantage of this way of training is that it is a lot more time consuming, since you have to take more rest between sets. If you do not have this time, then during your adjustment period you can also choose to simply maintain your muscle mass through training, but not to take muscle growth as an objective.

Only when you are fully fat-adapted can you then make the ‘switch’ to a training schedule that is focused on building muscle mass.

Until then, you can counteract the breakdown of your muscle mass by following the second important principle of strength training: the consumption of enough protein.

Eat enough protein .

Proteins are crucial for creating muscle mass. Proteins provide your body with the necessary building blocks (amino acids).

The following protein sources are suitable during a ketogenic diet :

  • Eggs
  • Red meat
  • Fish
  • Poultry
  • Full fat dairy

If you try to grow muscle mass or improve your performance during the ketogenic diet, it is recommended that you consume around 2.2 grams of protein per kilo of lean body mass .

The reason you take the fat-free mass as a starting point is because muscle mass is maintained by means of proteins. If you take the total weight as a starting point, then the body composition of the person is not taken into account.

For example, Person A can be very trained and muscular and weigh 80 pounds, while Person B also weighs 80 pounds, but is overweight and low in muscle mass.

Despite the fact that both people weigh 80 kilos, Person A has a much greater need for proteins because his muscle mass invites this to be maintained. Fatty tissue requires fewer proteins.

Now you think maybe? Lean body mass? What is that? And how do I calculate it?

You can calculate this mass by subtracting your fat percentage from your body weight. An example:

Suppose you weigh 88 kilograms and your fat percentage is 18.3%. Then you use the following formula:

88 x 0.183 = 16.104

The above calculation therefore indicates that you have 16.1 kilograms of body fat. You then deduct this from your total body weight:

88 – 16.1 = 71.9

Your fat-free mass is therefore 71.9 kilograms .

You now know that you need to consume approximately 71.9 x 2.2 grams of protein to grow muscle mass. This amounts to around 158 grams of protein per day .

When you sit far below this daily recommended amount of protein with your meals, you do not provide your body with enough building blocks to actually allow muscle growth.

Calculate macros

You can then use this number of grams of protein to calculate your intake of fats and carbohydrates, ie your macronutrients. How can you do this? We will give you a calculation example.

In the ketogenic diet, most of your daily calories come from fat. About 70-75%. Proteins around 20-25%. Carbohydrates make up 5% of your daily calories.

You can then calculate the daily composition of your macronutrients. Earlier you calculated what your protein requirement is. According to the example in this text, that was 158 grams.

Proteins have a calorific value of 4 kcal . In total, you therefore receive 632 kcal of protein. These 632 kcal make up 25% of your daily calories according to the ketogenic distribution of macronutrients, so a fourth part.

This means that your daily calorie requirement is around 4 x 632 kcal, ie 2528 kcal.

You can then calculate how many fats you can consume. Fats have a calorific value of 9 kcal. About 70% of your daily amount of calories should come from fats.

This means that 0.7 x 2528 = 1770 kcal of calories should come from fat. You then divide this number by 9 (calorific value of 1 gram of fat) and you arrive at approximately 197 grams of fat.

You calculate the number of carbohydrates in the same way: 0.05 x 2528 = 126 kcal. Divide this by 4 (calorific value of 1 gram of carbohydrates) and you will end up with 32 grams.

It is completely understandable if you do not feel like a rocket scientist with a calculator must calculate how much fat, protein and carbohydrates you can eat in a day .

With this calculator you can precisely match your macronutrients to the goals you have in mind with the ketogenic diet!

Eat the right amount of calories

Calories are important. With a calorie surplus, most people arrive, with a calorie deficit they lose weight.

You can influence the composition of your body (muscle building, fat percentage) by keeping an eye on the following components:

  • Eat enough protein to provide your muscles with nutrients
  • Eat less carbohydrates so that your body starts using fat as fuel
  • Train properly to stimulate muscle growth.

If you have these parts in good order, you will lose more fat if you are in a calorie deficit, and you will build more muscle when you have a calorie surplus.

An optimized diet for building muscle mass

  • Go with your consumption of calories about 250 to 500 kcal above your daily requirement
  • The extra calories must come from fat, not from proteins or carbohydrates (to prevent you from getting out of ketosis )
  • Keep the intake of proteins around 2.2 grams per fat-free mass
  • Depending on your experience with muscle building through strength training, you can determine how large your calorie surplus should be. In general, newcomers can use a larger surplus than people who have been working on muscle building for longer . This is because inexperienced strength athletes have relatively more ‘muscle gain’ to gain.

An optimized diet for fat loss

  • You want to maintain a calorie deficit that causes a weight loss of up to 1% body weight per week. This is important to actually maintain the muscle mass that you have.
  • If you are heavily overweight and have a high fat percentage, you can afford to lose more than 1% body weight per week .
  • You need to realize this calorie deficit by eating fewer fats.
  • Keep the intake of proteins around 2.2 grams per fat-free mass

Keep an eye on your hormones .

Hormones such as growth hormone cortisol insulin , testosterone and IGF-1 all play an important role in your body composition. They influence the production and maintenance of muscle and fat mass.

Many people think it is important to eat carbohydrates to be able to make these hormones. Carbohydrates indeed stimulate the production of such hormones, but they are not necessary.

When you exercise, your muscle cells become sensitive to growth hormones, insulin, testosterone and IGF-1. If you use enough protein for this, the amino acids from these proteins will stimulate the release of insulin and IGF-1.

What should be noted is that in people who have a low fat percentage and are also in ketosis for a long period of time with a calorie deficit, they have to be careful that their hormone balance is not disturbed.

In overweight men (high fat percentage), calorie-restricted diets have proven themselves as ‘testosterone boosters’. This is because these diets make the body healthier and fitter, because people lose a lot of fat (2) . The result is that you then have a healthier hormone level.

However, in people who have little fat, a ketogenic and calorie restrictive diet counterproductive work . Testosterone levels can fall to a level where, for example, the libido decreases (3) . And we don’t want that of course !!

If you already have a low fat percentage then it is advisable to carefully handle calorie restriction during ketosis.

Regarding the stress hormone cortisol, it is important to get enough sleep. If you do not get enough sleep then your body is more susceptible to stress factors and it will produce cortisol as a response. This hormone works against ketosis and fat burning.

If you want to get the best results from a workout, you will have to give your body the chance of a good recovery and a good night’s rest is an important part of this.

Drink enough water

It may be an open door that gets kicked in, but we want to emphasize it again. You really have to make sure that you drink enough water, especially if you exercise a lot during a ketogenic diet.

The ketogenic diet has a moisture-wicking effect and during exercise you also lose a lot of moisture. So it’s a double mechanism that is at work. Because of this you can get symptoms from the Keto Flu .

To make sure you keep your fluid balance in order and also to replenish the electrolytes that you lose during the day due to sweating and through your urine, it is recommended that you drink at least 3.5 liters of water.

As a woman you can afford to drink a little less, a man needs a little more water.

In addition, it is recommended to supplement your lost electrolytes with the mineral supplement from mother nature: SALT.

In his book Own The Day, Own Your Life , one of the most important tips that American health expert Aubrey Marcus gives to start a new day full of energy is as simple as it is effective.

He calls it the ‘Morning Mineral Cocktail’:

  • 350 ml of filtered water
  • 3 grams of sea salt or pink Himalayan salt
  • 1/4 th lemon squeezed in the water

The loss of electrolytes and minerals can be absorbed by using more sea salt.

Other ways to optimize your results of the ketogenic diet with strength training.

The use of supplements

MCT oil

The abbreviation MCT for MCT oil stands for Medium Chain Triglycerides. This is the English name for medium-chain fatty acids . The special thing about these fatty acids is that they are processed in a different way than long fatty acid chains.

In contrast to long fatty acid chains, MCT oil does not have to be broken down from the gallbladder with the help of bile. They are also not split and end up in the blood immediately after being absorbed by the intestine.

Long fatty acid chains, which are most common in our daily diet, cannot provide this quickly available energy.

By supplementing with MCT oil you can therefore provide yourself with energy from fatty acids that are easily processed by the body . The rapid absorption through the intestine ensures that the fatty acids can be quickly transported to the liver and then converted into ketones.

The best natural source of MCT oil is coconut oil . In addition, MCT oil is also available in pure form as a supplement. As a supplement to your diet, with this supplement you can ensure that you make fatty acids efficiently available to the liver, so that it can convert the fatty acids into ketones.

MCT oil is therefore an excellent way to provide yourself with an extra energy boost for your workout!

Krill oil

Krill oil and fish oil are both sources of DHA fatty acids and EPA fatty acids . These are omega-3 fatty acids that only occur in fish, crustaceans and shellfish.

Compared to fish oil, krill oil has proven itself in various scientific studies as a more effective and potent source of omega-3 fatty acids.

The difference between fish oil and krill oil is in the way in which the omega-3 fatty acids are ‘stored’ in the oil. With normal fish oil, those fatty acids are encapsulated in triglycerides .

The omega-3 fatty acids in krill oil, on the other hand, are encapsulated in phospholipids . These phospholipids are absorbed into the blood more easily, so that the fatty acids are absorbed more efficiently in the body.

The most important benefit with regard to muscle building is that the fatty acids from krill oil accelerate the recovery process of muscles by stimulating protein synthesis in the muscles.

A high-quality krill oil supplement is therefore a valuable addition to the ketogenic diet. 100% Pure Krill Oil from Foodie is such a high-quality supplement. It contains highly dosed omega-3 fatty acids that can be absorbed efficiently by the body through phospholipids (4) . 

In addition, 100% Pure Krill Oil from Foodie also contains the powerful antioxidant astaxanthin , the substance that gives the krill oil that beautiful red glow. This wonderful red powerhouse among antioxidants is attributed by scientific research the following health benefits:

  • Improved blood circulation (5)
  • Most active antioxidant against free radicals that are harmful to the body (6)
  • Improved skin, fewer wrinkles, better skin hydration in men and women (7)
  • Improved fertility in men, better sperm quality (8)


L-Citrulline is an amino acid that is used to stimulate ATP production . Both strength and endurance athletes can benefit from the use of citrulline because:

  • Aerobic endurance is improved (9)
  • Muscle endurance is improved (10) (11)
  • Muscle strength is increased
  • Muscle recovery is speeded up (12)

Beta Alanine

This is an amino acid that can increase muscle endurance (13) .

A 2015 study showed that a daily dose of 4 to 6 grams of beta-alanine improved training performance for 2 to 4 weeks.

It is mainly a work affair in the field of the glycolitic system, in which longer sets of 8 to 15 repetitions must be supplied with energy.

As we discussed earlier in this article, the glycolithic system is disrupted due to a lack of carbohydrates during the initial phase of the ketogenic diet.

Because beta-alanine provides extra stamina in this domain, it is an ideal supplement for ketogenic strength athletes.

Exogenous ketones

You probably know them, the sweet yellow energy drinks in plastic bottles that you often see in sports canteens. Such sports drinks have been developed to provide you with a good shot of sugar just before exercising so that you can use this energy directly for physical efforts.

When you are in ketosis you want to avoid any kind of sugar because you want your body to use fat as fuel. For people in ketosis who have a direct need for energy before or during exercise, they can use exogenous ketones in such a case. It is therefore an energy drink based on ketones instead of sugar.

Exogenous ketones enable your body to immediately use ketones as fuel. Although this does not get you into ketosis, you do benefit from the benefits of ketosis. Think of more energy, a better focus and better physical and mental performance. Exogenous ketones also help you to get back into ketosis if you have ingested too many carbohydrates.

Introduce carbohydrate consumption around training

During ketosis, the performance during strength sessions can therefore be reduced. In such cases, it may help to replenish glycogen stores .

You can do this in two ways. By means of a targeted ketogenic diet (TKD) , in which you consume approximately 25 to 50 grams of carbohydrates just before the start of your sports session.

A second way is to follow a cyclic ketogenic diet (CKD) , where you follow a strict ketogenic diet for 5-6 days and use 1-2 days to supplement glycogen stores. On these days you will therefore need a carbohydrate-rich diet.

More information about these variants of the ketogenic diet can be found on pages about the Targeted Ketogenic Diet and the Cyclic Ketogenic Diet .


In this article we discussed how you can combine the ketogenic diet with your strength sports sessions.

We have identified the five most important principles that you must follow to achieve optimum results:

  • Train well.
  • Eat enough protein
  • Eat the right amount of calories
  • Keep an eye on your hormones
  • Drink enough water

In addition, you can use supplements such as creatine, citrulline and beta-alanine to give your endurance a boost during workouts.

You can also replenish your glycogen reserves by consuming carbohydrates around your workouts (targeted ketogenic diet) or by supplementing your glycogen stores once or twice a week ( cyclic ketogenic diet).

Of course, not everyone is a strength athlete who wants to become muscular and broad in the gym!

Others prefer to focus on endurance sports such as running and cycling. These people can indulge themselves with the article Ketogenic Diet and Endurance !

Fan of everything health and fitness related. My mission is to share my knowledge and experience with as many people as possible and help them to find their ideal path to perfect health.

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