Creatine definition

Creatine is a non-essential amino acid found in the diet, mainly in meat, poultry and fish, at around 5 g per kg.

The body produces it according to its needs (between 1 and 2 g per day) from the protein foods consumed.

It is found in 95% of skeletal muscles.

It is synthesised in the kidneys, liver and pancreas.

Commercial creatine is a synthetic derivative produced by a chemical reaction between sarcosine sodium and cyanamide.

Sold as a soluble or semisoluble powder, tablet, lozenge or liquid, creatine is considered a dietary supplement.

It is not uncommon for other nutrients to be added to enhance its effects: glucose, proteins, vitamins, minerals, RNA (ribonucleic acid), glutamine, taurine or certain plant extracts.

It is believed that taking a creatine supplement can help increase the phosphocreatine content of skeletal muscle and improve exercise performance in certain activities.

Phosphocreatine, stored in skeletal muscle, is a precursor to adenosine triphosphate (ATP), which provides energy to muscle cells.

Increasing creatine levels in the body would promote ATP renewal during short bursts of intense exercise and accelerate phosphocreatine synthesis after exercise.

Creatine also promotes water retention in the muscles, which increases body weight and muscle volume.

What is creatine used for?

Probable effectiveness

• Slightly improve the ratio of muscle mass to fat mass during exercise (more muscle, less fat)
• Improve physical performance (intense exercise and short duration)
• Improve neurological disorders associated with creatine deficiency

Efficacy uncertain

• Treat heart failure
• Reduce symptoms of certain muscular disorders
• Reduce glucose levels in people with diabetes

Probably ineffective

• Improving physical performance (endurance)

Dosage

Caution: Creatine is not effective for improving performance in people who participate in endurance sports. It also increases the risk of cramping and dehydration during this type of exercise.

Increase muscle mass and athletic performance (only intense, short bursts of exercise):

• Take 2g to 3g per day

Warning: It is recommended that you drink 2 litres of water per day to counteract the dehydration that creatine can cause.

Note: Some sources recommend an attack dose of 20g per day (4 x 5g) for 4 to 6 days, followed by a maintenance dose of 2 to 3g per day. A loading dose of 9g per day for 6 days has also been tested. However, a dose of 3 g per day for 1 month without an attack dose also appears to be effective.

Contraindications

People with diabetes or kidney problems should avoid creatine unless under medical supervision.

There is insufficient data on the safety of creatine in children, pregnant or breastfeeding women.

Side effects

Occasionally: gastrointestinal pain, nausea, diarrhoea and muscle cramps.

Cases of seizures, arrhythmias, cardiomyopathies, venous thrombosis, rhabdomyolysis (rapid muscle breakdown) and renal failure have been reported.

The link between these symptoms and creatine has not been established, but caution should be exercised.

Interactions

With plants or supplements

Consuming large amounts of caffeine may negate the beneficial effects of creatine on exercise performance.

Caffeine (and ephedrine) combined with creatine may increase the risk of side effects associated with creatine use.

With medication

Although no cases have been reported, it is advisable to avoid creatine if you are taking any medication that is toxic to the kidneys.

Creatine may increase the adverse effects of caffeine and ephedrine mixtures.

Food sources

• Herring contains 6.5 to 10g/kg
• Pork contains 5g/kg
• Beef contains 4.5g/kg
• Salmon contains 4.5g/kg
• Tuna contains 4g/kg
• Cod contains 3g/kg
• Milk contains 0.1g/kg
• Cherries contain 0.02g/kg

Based on the data in this list, animal meat contains the highest amounts of creatine. For example, there is about 3-5g of creatine per pound of raw fish, such as salmon and tuna, and meat, such as pork and beef.

Herring has the highest creatine content, with up to 10g per kilo. However, the way these foods are cooked can destroy some of the creatine.

The amount of dietary creatine in omnivores can therefore be reduced depending on how these foods are prepared.

It is important to note that dietary creatine intake is not the same for everyone.

In fact, it has been suggested that creatine and β-alanine supplementation may be particularly useful for vegan athletes because vegetarian diets promote lower muscle creatine and muscle carnosine levels in consumers.

People on a normal diet with a protein intake of up to 2g/kg body weight can get between 0.25 and 1g of dietary creatine per day.

And while it is possible to increase your intake by eating more creatine-rich foods, it would be quite difficult to get more than 4g/day because you would have to eat a lot of it, fish or meat.

In fact, to get 3 to 4g of creatine a day, you would need to eat a pound of beef, pork or herring, or even more depending on how you cook it, which is not at all obvious.