What is creatine?
Creatine, also known as methylglykozyamine or creatine, is a substance that is made in the human body. 90% of the creatine is found in the skeletal muscles. The substance contributes to the energy supply to the muscles.
It is not uncommon for creatine to be confused with creatinine. Creatinine is a breakdown product and the excretion form of creatine.
The biosynthesis of creatine
Creatine is contained in various foods, but is also synthesised by the human body itself. Around 1 to 2 g are produced in the liver every day. The pancreas and kidneys are also able to produce creatine.
Guanidino acetate is a prerequisite for creatine synthesis in the body. Guanidinoacetic acid is formed by guanylation of the amino acid glycine and subsequent methylation in creatine. The amino acids arginine and methionine also play a role in the production of the substance.
The creatine enters the blood via the liver or the other producing organs and is transported to the target organs via the blood vessels. The skeletal muscles and the heart muscle especially require creatine. The target organs also include the brain, nerves, and retina in the eye.
Creatine - Chemical properties
Although the body needs different amino acids for creatine synthesis, creatine itself is not assigned to the amino acids. It is rather a guanidinium compound with an empirical formula C4H9N3O2. This is characterised by a central carbon atom that is linked to 3 nitrogen atoms.
Creatine effect and function
Creatine has a special role in the generation and supply of energy to the muscles and other physical structures.
Energy supply through creatine
The substance creatine can be converted into the form of creatine phosphate by the enzyme creatine kinase. Creatine phosphate serves as a short-term energy reserve for the muscle. The muscle needs energy in the form of ATP (adenosine triphosphate) for its contraction.
The ATP separates one of the 3 phosphate molecules and thus becomes an adenosine diphosphate (ADP). This process releases energy that the muscle can use for contraction.
The processing operation in the brain and many other metabolic processes also use ATP to generate energy.
However, the supply of ATP is very limited and therefore only lasts for a short period. The muscle can only contract one to three times on average with its ATP supply. In order for the muscle work to be maintained during physical activity, a resynthesis of ATP is required.
This is where creatine comes to play in the form of creatine phosphate. By splitting off the phosphate residue and transferring it to ADP, ATP is created again. At a later point in time, further reaction paths for resynthesis and energy generation will be available. However, creatine phosphate is the energy source that is used first in the muscle after the ATP storage has been used up.
Creatine protects the body cells
Creatine phosphate also appears to contribute to protecting the cell walls, the so-called cell membranes. The substance can bind to the cell membrane, thereby contributing to its stability.
Cell hydration, cell volume and creatine
When creatine gets into the cells, it brings water with it. This increased cell hydration also increases the cell volume. The cell volume plays an important role in protein metabolism and DNA synthesis. The synthesis of the storage carbohydrate glycogen is also closely related to the volume of the body's cells.
Other effects of creatine:
- can increase physical performance
- has a positive effect on cognitive performance
- increases lean body mass
- reduces symptoms of fatigue
- can improve general well-being
Creatine is produced in the liver from the amino acids arginine, glycine and methionine. This requires the enzymes glycine amidinotransferase, guanidinoacetate methyltransferase, and methionine adenosyltransferase.
This way, 1 to 2 g of creatine are produced in the body every day. The kidney and pancreas are also able to produce creatine to a certain extent.
But creatine is not only produced by the body itself, it can also be absorbed through food. If more creatine containing foods are incorporated into the menu, the body's own production can be lower.
Fish, such as herring, salmon or tuna, are among the foods that are particularly high in creatine. Pork and beef also contain a comparatively large amount of creatine. For people who live a vegan lifestyle, the supply of creatine is therefore somewhat more difficult.
The body is able to store creatine. How much creatine is stored depends, among other things, on gender, the proportion of muscles and the total body weight. The total body inventory of creatine in an adult male weighing 70 kg is approximately 120 g. More than 90% of this creatine storage is found in the muscles.
A creatine supplementation lasting several days leads to an increase in creatine in the blood plasma as well as to an increased concentration in the creatine storages in the body.
Creatine is one of the most popular nutritional supplements, especially for athletes who build up their muscles. Various forms of creatine are available for supplementation.
Not every person reacts equally to the individual forms. So there are so-called non-responders, where taking creatine monohydrate does not bring the desired results. Here, switching to another form of creatine may make sense.
The standard in creatine supplementation is creatine monohydrate. Most scientific studies also refer to this form. Creatine monohydrate has a good absorption rate and is usually well tolerated. Creatine monohydrate consists of 88% pure creatine and has a monohydrate content of 12%.
The water content of the creatine anhydrous or anhydricus was removed. As a result, the creatine concentration is higher than that of creatine monohydrate. Using this form shows neither advantages nor disadvantages as compared to creatine monohydrate, but creatine anhydrous is usually more expensive.
Micronised creatine is a special form of creatine monohydrate. In a mechanical process, the particle size of the creatine is reduced during production. This increases the water solubility. When it comes to supplementation, however, there are hardly any differences as compared to 'normal' creatine monohydrate.
Creatine hydrochloride (Creatine HCl)
In creatine hydrochloride, a creatine molecule is coupled to a hydrochloride group. This should increase the absorption of creatine. So far, however, this assumption has not been scientifically proven. However, it appears that the substance breaks down in the stomach into hydrochloride and free creatine. The absorption rate does not differ from the absorption rate of creatine monohydrate. However, the price of the simple creatine monohydrate is superior.
Creatine is also available in a fluid form as a liquid. This is the creatine monohydrate dissolved in liquid. However, this form of creatine has proven to be ineffective in the supplementation.
When dissolved in water, creatine is extremely unstable and breaks down into the useless degradation product creatinine after a few days. This is excreted through the kidney.
Kre Alkalyn - Buffered creatine
Kre Alkalyn is buffered creatine monohydrate, which has a higher pH value. This should increase the absorption rate and the creatine should reach the muscle cells more easily. However, comparative studies have so far not shown any differences in the effect or the accumulation in the muscle cells.
Creatine ethyl ester
Creatine ethyl ester is a derivative of creatine monohydrate, which has an additional ester compound. The pure creatine content is 82.4%. In studies, creatine ethyl ester has been shown to be less suitable for building muscles. The supplementation led to increased blood serum levels of creatinine, but the creatine concentration in the muscles did not increase.
Creatine magnesium chelate
Creatine chelated with magnesium has an effect similar to that of low-dose creatine monohydrate. This form of creatine could be useful if you want to improve muscle strength but avoid increasing the body's water content.
Creatine nitrate is a form of creatine in which nitrate (NO3) is linked to the creatine molecules. This form has better water solubility, but has no other advantages.
Creatine citrate is creatine bound to citrate or citric acid. Although this variant dissolves better in water, the absorption and the effect of creatine does not change.
There are other forms of creatine which, however, have no advantages in use compared to creatine monohydrate. These forms include:
- Creatine alpha-ketoglutarate
- Sodium creatine phosphate
- PEG creatine
- Creatine pyruvate
In contrast to other nutrients and vital substances, the German Society for Nutrition (DGE) does not issue any official recommendations for creatine. The daily requirement for creatine is between 1 and 6 g depending on the physical activity. People who do not exercise a lot need less creatine than athletes. The body produces between 1 and 2 g of creatine a day, the rest of the need has to be met through the diet.
Creatine in bodybuilding
When bodybuilding, the active body styling is the focal point. A strong growth in muscle mass is usually just as desirable as a good definition of the muscles.
Many bodybuilders take part in competitions which they prepare for with a lot of discipline. In addition to targeted muscle training, cardiovascular exercises, and a reduced-calorie diet, supplements are also used to increase the lean body mass. One of these supplements is creatine, which around 50% of bodybuilders consume in preparation for a contest.
Various studies suggest that it can make sense to support muscle building during bodybuilding with the supplementation of creatine. The use is also not a problem when participating in competitions, since creatine is not on the doping list as a dietary supplement.
Create muscle volume with creatine
Creatine is popular among bodybuilders primarily because of its osmotic effects. The creatine molecules draw water into the muscle cells. As a result, the muscle cell gains volume and the muscle appears plump and larger. This explains the weight gain of 0.5 to 2 kg, which can already be seen after a 5-day supplementation.
It is worth noting that the actual muscle building is not affected by the water retention. On the contrary: Creatine can have a positive effect on the muscle growth.
Creatine in competitive sports
Creatine is not only suitable as a supplement for bodybuilders and people who do weight training. Competitive athletes doing other sports can also benefit from the supplement.
According to a study from 2010, creatine can improve both the performance in sports and promote strength and endurance. Strong muscles play a role in various types of competitive sports. The use of creatine can therefore be useful in bicycle racing or in athletic sports.
The increase in creatine in the muscles that can be achieved by taking creatine accelerates ATP resynthesis. This is particularly important for intense and short-term training. Therefore, more and more short-distance runners and / or swimmers use creatine.
Creatine and muscle building
Creatine plays an important role in muscle function. Several studies show that the substance can have a positive effect on muscle development.
Creatine in the muscles
Basically, it should be noted that the supplementation of creatine usually leads to an increase in the creatine content in the muscles. Most dietary supplement studies use creatine monohydrate.
How much creatine ultimately arrives in the muscle is highly individual and not solely dependent on the dosage. In addition, there are so-called non-responders, in which the intake of creatine monohydrate for reasons that have not yet been clarified has no effect on the level of the muscle creation.
It is also interesting to note that a vegetarians' muscle creatine level increases more than those who eat meat and animal products after taking creatine. This may be due to the fact that vegetarians consume less creatine through their food and thus have a lower creatine storage.
Increase lean body mass with creatine
The lean body mass (LBM) is the lean mass of the body, so the fat-free body mass. Basically, the LBM consists of the organs, the bones, the brain, the water in the body and the muscles. The LBM can be determined using various measurement methods.
Since the weight of organs, bones and brain hardly changes, an increase in LBM means an increase in muscle mass and / or an increase in the water content. In several studies, the creatine intake increased the lean body mass. This is particularly desirable when bodybuilding.
However, it remains mostly unclear whether the LBM has changed positively due to an increase in muscle mass or due to water retention in the muscle cells.
Creatine and strength
People who want to build muscles usually also pursue the goal of achieving higher muscle strength. Study results also indicate a positive effect of creatine.
A study by Spillane et al. from 2009 showed a significant increase in muscle strength after creatine supplementation in combination with strength training.
The study participants received a dose of 0.3 g of creatine per kg body weight for the first 5 days. From the 6th to the 42nd day, the dose was reduced to 0.075 g of creatine per kg body weight. The average daily dose was 20 or 5 g of creatine.
A study by Cramer et al. suggests that a short-term intake of creatine can significantly improve muscle strength. The subjects in the study only consumed 10.5 g of creatine over a period of 8 days and also carried out isokinetic training for 3 days.
Despite the short duration of supplementation, there was an increase in muscle strength. In particular, people in rehabilitation and athletes after injuries could benefit from the nutritional supplement.
Creatine against muscle weakness
When you hear the term creatine, you usually think of athletes or bodybuilders. But people with chronic diseases can also take creatine to relieve their symptoms. Creatine intake seems to have a positive impact, especially in people with muscular dystrophy.
Muscular dystrophy includes various muscle disorders that are caused by a mutation in the genome. A defect or a lack of protein in the muscles leads to muscle weakness and muscle atrophy.
The most well-known muscular dystrophy is the Duchenne form. It begins in early childhood, progresses quickly and is not curable. The children affected show slight muscle weakness during the 3rd to 5th year of life and between the 7th and 12th year most patients need a wheelchair.
Creatine against muscular dystrophy
In patients with the Duchenne muscular dystrophy, less creatine is found in the muscle cells and also in the blood serum. Various studies have therefore investigated whether creatine supplementation can help these patients.
For example, Felber et al. administered creatine to a boy with muscular dystrophy over a period of 155 days. During this time, the child's muscle performance improved noticeably. A clear success when you consider that the disease is actually progressing rapidly.
Studies with more subjects also come to a similar result. The children with muscular dystrophy had more strength in their hands and legs after taking creatine. They could climb stairs faster or cover certain distances.
They also reported an improved general condition. The parents as caregivers were able to confirm this change.
Creatine and performance enhancement
Creatine is becoming increasingly popular with athletes to improve performance. One advantage of the substance is that, despite its performance-enhancing properties, it is not on the doping list.
In the 1999 study, Volek et al. was able to show that creatine can improve performance in weight training. Subjects who received 25 g of creatine per day for a week and 5 g of creatine for a further 10 weeks were able to increase their leg press performance by 32% after 11 weeks of training. In the control group receiving a placebo, performance only improved by 24%.
A meta study from 2003 also confirms that creatine has a positive influence on performance in weight training. The authors based their research on 22 studies. Taking creatine in these studies resulted in a performance increase of around 8 to 45% in the subjects' workout, depending on the exercise.
Creatine even in endurance sports?
In contrast to strength athletes, endurance athletes do not benefit as much from taking creatine. For example, researchers mostly found no effects of creatine on athletes' performance in endurance sports such as swimming, running, or rowing.
In a study from 2003, creatine caused a lower lactate level in rowers and presumably also because rowers were able to maintain their performance for a longer time.
But why does creatine, in contrast to weight training, not have such a clearly positive effect on endurance sports? Creatine is mainly used in muscles for short-term energy production. The longer the physical exertion lasts, the more the aerobic energy supply processes such as the aerobic-glycolytic energy metabolism or the aerobic lipolysis is outweighed. Here the creatine no longer plays such an important role.
Creatine and cognitive skills
With creatine supplementation, the focus is mostly on physical performance improvement. But muscles are not the only body structures that process creatine. The brain and nerve cells also need creatine.
McMorris et al. achieved a clear effect of creatine in terms of cognitive abilities in her study with older study participants. They received 5 g of creatine per day. Using various tests, the researchers were able to demonstrate that creatine can increase mental performance in older people. For example, they were able to do better memory tasks and keep and replicate sequences of numbers more securely. This cognitive skill improvement occurred after just one week of creatine supplementation.
In another study, McMorris et al. examined the relationship between sleep deprivation, creatine and cognitive performance. To do this, they deprived the test subjects of their sleep for 24 hours and had them perform various cognitive tests. One group received a placebo preparation, the other group creatine. The result: The participants in the creatine group managed the tasks even better after being deprived of sleep than the subjects in the placebo group.
Memory performance in vegetarians
In addition to older people, vegetarians also seem to respond particularly well to creatine supplementation. A study of 45 vegetarians revealed remarkable effects of creatine supplementation on intelligence and working memory.
After taking 5 g of creatine per day for 6 weeks, the subjects in a study from 2003 showed a clear improvement in their cognitive abilities. The creatine supplementation had a positive influence on the memory function and the study participants also performed better in the intelligence test.
Creatine and regeneration
Athletes can only optimise their endurance and muscle gain with the right regeneration. Training-induced muscle damage occurs after high-intensity weight training or demanding endurance sessions.
In the case of primary muscle damage, the small functional contraction units of the muscle, the muscle cell membrane or the cell organelles are changed morphologically and their function is impaired.
The secondary muscle damage is delayed due to an inflammatory reaction as a result of intensive training. Both primary and secondary muscle damage can reduce the maximum strength of the muscle and cause pain (sore muscles).
Creatine against training related muscle damage
It is still scientifically controversial whether the use of creatine for a faster regeneration after training-related muscle damage is helpful. For example, in one study, untrained men who took creatine 5 days before and a week after intensive muscle training had low creatine kinase levels in their blood.
Creatine kinase is an enzyme that is found in both muscle cells and the brain. Increased blood CK levels after muscle training indicate muscle injuries. Since the subjects had lower blood levels after taking creatine, it can be assumed that the supplement has a muscle-protecting and regeneration-promoting effect.
The participants in the study who took creatine also showed higher strength values in the recovery phase in both isokinetic and isometric training exercises than the subjects in the comparison group.
In another study with young athletes, creatine also had a positive effect on regeneration. The athletes, who took 20 g creatine daily, not only had lower CK levels in the blood after a strenuous bicep workout, but also less pain in the arms. The range of motion of the arm after training was also larger than that of the study participants who only took a placebo preparation.
However, not all studies were able to confirm the regenerative properties of creatine. Especially with eccentric training there was no effect.
Creatine protects the muscles
Creatine can reduce muscle damage in various ways and thus accelerate the regeneration:
- Creatine counteracts inflammatory reactions in muscles after exertion
- Creatine prevents oxidative damage to muscle cells
- Creatine contributes to the calcium balance in the muscle
Creatine and depression
Depression is one of the most common mental illnesses. In Germany alone, almost 6 million people between the ages of 18 and 65 suffer from depression each year. 19% of the population develop a depressive disorder at least one time in their life. This disease affects women about twice as often as men.
Depression symptoms include:
- Sleep disorders
- Constant brooding
- Motivation problems and slackness
- Difficulty concentrating
- Fatigue and exhaustion
- Inner unrest
- Feeling of worthlessness
Within the frame of a depression, physical signs can also occur. For example, indigestion, muscle tension or chronic pain can also be the result of a depressed mood.
Causes of depression
Depression can have different causes. With regard to the effectiveness of creatine in the (supportive) treatment of depression, two aspects are particularly interesting.
On one hand, a lack of hormones and neurotransmitters in the brain can promote depression. These primarily include the messenger substances serotonin and noradrenaline. Therefore, many patients with depression in therapy also receive so-called selective serotonin re-uptake inhibitors (SSRIs).
On the other hand, researchers from the Ulm Department of Clinical and Biological Psychology have found that the mitochondria, the 'power plants' of the cell, produce less ATP in depressed people. The decrease in mitochondrial performance correlates with the extent of the mental illness.
This quite new aspect in the research into the causes of depression is particularly interesting because creatine is known to improve the ATP supply.
Creatine in the treatment of depression
Various studies indicate that the use of creatine as a dietary supplement can be useful in the treatment of depression.
In a 2011 study, 15 women with SSRI-resistant depressive disorder received 4 g of creatine per day for 8 weeks. During this period, their symptoms improved significantly. However, there was no comparison group in this study and only a very low number of participants.
However, a randomised double-blind study came to a similar result, in which the researchers combined the serotonin re-uptake inhibitor Escitalopram with 5 g creatine monohydrate or a placebo agent in the same amount daily. After only 2 weeks, the combination of Escitalopram and creatine led to an improvement in the symptoms.
While monotherapy led to remission in 26% of the participants, it was twice as many test subjects in the creatine group with 52 percent, who reported a permanent reduction in their symptoms.
Creatine and bipolar disorders
In a 2007 study, Roitman et al. was also successful with creatine in the treatment of depression. Taking them in addition to the antidepressants led to an improvement in the symptoms measured using the Hamilton depression scale and the Hamilton anxiety scale.
However, the positive effect was only detected in people suffering from unipolar depression. The bipolar study participants developed a mania on the other hand.
The study was rather small and the number of subjects was small. It is therefore unclear whether the results can be generalised. People suffering from a bipolar disorder, e.g. are manic-depressive, should still refrain from taking creatine until further research on this aspect is available.
Creatine in medicine
Creatine is not only used as a dietary supplement in sports, but also in medicine as an auxiliary therapy in the treatment of various diseases. For example, the substance can improve muscle strength in muscle diseases such as muscular dystrophy.
Creatine for ALS
Scientific studies also provide evidence that creatine can also be helpful for patients with ALS (amyotrophic lateral sclerosis). Amyotrophic lateral sclerosis is a disease from the group of motor neuron diseases. The incurable disease is characterised by a progressive and irreversible degeneration of the muscle-moving nerve cells.
Since the disease is not curable, the focus in treatment is on symptom relief. Creatine can be used to support the treatment of symptoms, especially in the short term and in the event of temporary stress.
Creatine dosage and intake as a supplement
Creatine is available as a supplement not only in different forms, but also in different administration variants. For a quick effect, a loading phase at the beginning of the intake is recommended for creatine monohydrate.
The most common form of creatine supplementation combines a charging phase with a maintenance dose afterwards. During the loading phase of 5 to 7 days, 0.3 g of creatine per kg of body weight are taken daily. The daily dose is on average 20 to 25g creatine. This is followed by a supplementation of 0.03 g creatine per kg body weight per day. For a person weighing 82 kg, this would be around 2.5 g of creatine per day.
Charging phase benefits
Due to the high starting dose, the muscle memory fills up with creatine within a very short time. This also increases the maximum force. With the help of the loading phase, you can quickly determine whether you are a non-responder. Most of the current research studies work with a charging phase.
Creatine is available as a dietary supplement in the form of a white powder. This is odorless and tasteless and can simply be stirred into water or fruit juice. Fruit juices have the advantage that they contain short-chain carbohydrates, which can promote the transport into the cells.
If you do not want to take powder, you can also take capsules. These contain a standardised amount of creatine and are also suitable as a supplement.
Creatine and fluids
In any case, creatine should always be taken with plenty of fluids. Even after ingestion, it is advisable to drink a lot throughout the day because creatine binds water. In this way, the creatine can be better absorbed by the body.
Creatine in food
The body can produce creatine itself, but it can also absorb creatine through food. Food of animal origin contains a particularly large amount of creatine. Meat contains an average of 5 g of creatine per kg, fish contains 2 to 10 g creatine per kg depending on the species. On the other hand, there are only small amounts of less than 0.1 g of creatine per kg in plant based foods as well as in milk and dairy products.
Creation content of selected foods (grams per kg):
- Beef: 5
- Chicken: 3.4
- Rabbit: 3.4
- Pig heart: 1.5
- Liver (uncooked): 0.2
Creatine when cooking
Depending on the cooking temperature and other ingredients, creatine can be converted into the toxic substance N-methylacrylamide during the cooking process. In addition, part of the creatine is converted into the ineffective creatinine.
Creatine and protein
The rumor that creatine and whey protein should not be taken together persists in the bodybuilding and nutrition scene. It is said that the protein would hinder the uptake of creatine. In fact, the uptake of carbohydrates and / or proteins improves at the same time.
It is particularly important that the creatine is taken as soon as possible before and / or after training.
Creatine shows little interactions. The substance should not be taken together with so-called nephrotoxic substances. These include, for example, non-steroidal anti-inflammatory drugs such as Ibuprofen and Cyclosporine.
Taking creatine with ephedra increases the risk of stroke and other serious side effects.
So far there have not been many scientific studies dealing with creatine overdose. However, there is evidence from animal experiments that a short-term high-dose intake of 5 g creatine per kg body weight or a long-term intake of 1 g creatine per kg body weight can lead to kidney and liver damage. However, since a maximum of 20 g creatine per day is sufficient for a good effect, extremely high doses of creatine are normally not recommended and not used.
Creatine side effects
Taking creatine is considered relatively safe. Side effects occur very rarely and if so, only with high doses. Potential side effects include:
- Muscle cramps
- Stomach pain
- Heat intolerance
Can creatine damage the kidneys?
There are always reports that high doses of creatine damages the kidneys. However, there is hardly any scientific evidence for this. Creatine is broken down in the body in creatinine. This substance is excreted through the kidneys.
In kidney failure or other serious kidney disease, the kidney's ability to filter is restricted and urinary substances remain in the blood. Elevated creatinine levels are therefore considered a marker for kidney damage.
Now there can be an increase in creatinine in the blood even while taking creatine. However, this is mainly due to the fact that when creatine is taken, more creatinine is produced and in no way has to be attributed to kidney damage.