Creatine is a protein that is naturally present in your muscles and is involved in supplying energy. Creatine supplements, which are well known in certain sports, may have many possible benefits for the body and athletic performance, including increased muscle mass and optimised energy use and power. This article discusses frequently asked questions about creatine.
1. What is creatine?
Creatine is a nitrogenous compound produced mainly by the kidneys, liver and pancreas, obtained from non-essential amino acids.
A man weighing 70 kg has around 120 g of creatine in his body, 95% of which is stored in muscle tissue. Creatine synthesis can vary, especially when intake from food is low. The body can increase production so that levels remain stable. This phenomenon ensures a stable amount of creatine in the body. This means that even vegetarians will have a stable and sufficient level of creatine for proper functioning.
2. How much creatine does an individual need?
Most people need 2 g of creatine each day. Athletes with high muscle mass need 1 to 2 g more per day on intense training days.
There are no specific foods that should be eaten to increase creatine levels because the compound can be produced by the body in sufficient quantity to meet the body's needs, especially in the case of power athletes or those building muscle who benefit from greater protein intake.
3. How does creatine work?
Creatine produced by the body is carried through the blood to organs where it is stored, such as the muscles. It is then transformed into a compound called phosphocreatine (PCr). This is a small source of energy, lasting only a few seconds. PCr is very useful at the beginning of short, high-intensity workouts. PCr also helps build up reserves of ATP, the energy molecule that provides power during muscle contraction.
4. Can you get creatine from food?
The amount of creatine varies significantly depending on how you eat.
Meat, poultry and fish have high levels of creatine, with around 4 to 5 g of creatine per kg. Milk, on the other hand, has only 0.1 g/l.
Vegetarians get almost no creatine from their diets and rely on their bodies to produce it.
Regardless of your diet, you will not be at risk for creatine deficiency.
5. What are the benefits of increasing creatine intake?
PCr is 3 to 5 times more concentrated than ATP in the muscles. In terms of available energy, it is more quickly used up than the energy from carbohydrates. This is even more true when compared to energy from fats.
In theory, creatine energy reserves are not as important as those from other nutrients.
What makes creatine different is that it is immediately available at the start of a workout, contrary to other energy sources which are not available as quickly.
When taking creatine supplements, the body reduces its own production, starting again sometime over the four weeks after you stop taking it.
Taking creatine supplements is therefore questionable. The creatine is added to that provided by food and replaces that produced by the body. There are very few benefits to doing so.
6. Does creatine play a role in sports activities?
An athlete's body does not have considerably greater needs in creatine and there are no specific diet recommendations. Food and the body's own production provide enough creatine to meet the body's needs. No deficiency - or even borderline deficiency - has ever been observed in athletes. Creatine supplements exceed the body's physiological needs.
One of the main reasons for taking creatine supplements is to increase levels of it in the muscles in order to increase anaerobic capacity without lactic build-up (short bursts of effort). This makes it possible to work out at high intensity for slightly longer periods of time and delay exhaustion of ATP levels. This is relevant for very brief exercises of 15 secs max. Next, the anaerobic glycolysis system takes over, with available energy stores that are 300 times greater than PCr.
The goal of taking creatine is not to "delay fatigue" but rather delay exhaustion of ATP during brief, intense, repeated exercises, such as sprints, weightlifting or repeated throwing.
Unfortunately, the term "fatigue" is often used incorrectly which can mislead consumers.
7. What effects do creatine supplements have on health?
Muscle cramps have been observed repeatedly due to dehydration in warm environments.
The most frequently stated complaints against creatine are possible harmful effects on kidney function. Further research has been done on creatine supplements. The authors have recommended that before taking any supplements, athletes in good health should visit a doctor to see if they have any kidney problems, even minor ones. Visits should be repeated regularly (every three months) while taking supplements. Supplements should be stopped if any health problems arise.
8. What precautions should be taken when taking creatine supplements?
Regardless of the type of creatine supplements, whether they are taken in high quantities or loading doses, or over the short, mid or long term, the possible effects and potential risks are not well known.
Caution should be exercised when using this product. Some have demonstrated positive effects on certain performances, but these remain specific cases. Numerous claims, which outnumber current scientific evidence on the subject, seek to promote a product which is still not well understood.
9. What kinds of creatine supplements are available?
Creatine is generally found in powder form, but it is also available in tablets, gels, syrups and drinks. It can be found as a single supplement or mixed with carbohydrates or proteins, vitamins, mineral salts or amino acids.
Some say that it is more efficient in powder form for power sports and tablets for endurance sports, but there is no scientific evidence to support such claims. You should remain alert regarding promises about improving power and performance, which are often unsubstantiated.
10. Creatine and AFSSA's view
The French Food Safety Administration has issued the following opinion:
- Remember to eat a varied, balanced diet and drink enough water as appropriate for athletes in accordance with the recommended daily allowances;
- A sufficient amount of creatine is found in foods or produced by the body to meet physiological needs, without any deficiency being observed and without supplements being required to maintain the recommended level in the body;
- Taking creatine supplements leads to body weight and muscle mass increases of under 3% and 10%, respectively and are often due to water retention and not protein development;
- Any claims, especially with regards to strength, speed or power, events or exercises relying on anaerobic glycolysis or aerobic performance, lactic acid, blood ammonia, protein biosynthesis, fatigue, motivation, muscle tone, fitness level or aggressiveness, have not been substantiated with scientific proof and are therefore considered unfounded;
- The only claims that have been investigated through significant scientific studies shown inconsistent results and pertain to repeated, high-intensity exercises lasting 15 seconds or less;
- The use of creatine supplements presents a risk which is today insufficiently known, in particular for long-term use, to the health of the consumer with a potential carcinogenic risk;
- Current knowledge needs regular scientific review both with regards to consequences to health and on performance.
Source: Afssa Opinion January 2001