Creatine

Highlights:

-Creatine monohydrate is proven to increase lean body mass if combined with resistance exercise

-Other forms of creatine have questionable benefits

-Creatine is safe but it may aggravate asthmatic conditions

-Only micronized creatine should be used

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Creatine monohydrate is one of very few dietary supplements that are scientifically proven to help increase lean muscle mass (if used together with exercise and proper diet).

What is creatine

Creatine is a nitrogenous organic acid, produced naturally in the kidneys and liver from three amino acids: L-arginine, glycine, and L-methionine.

The main role of creatine is supplying energy to body cells (mostly to muscle cells) by increasing the formation of ATP (adenosine triphosphate). Some 95% of all creatine in our body can be found in skeletal muscles with small amounts also stored in brain and testes.

The gains in muscle mass seem to be a result of an improved ability to perform high-intensity exercise throufh increased PCr availability and enhanced ATP synthesis, thus enabling an athlete to train harder and promote greater muscular hypertrophy through increased myosin heavy chain expression possibly due to an increase in myogenic regulatory factors myogenin and MRF-4.^3,4,5

Sources of creatine

Under normal circumstances we get about half of our creatine from the meat and the other half is synthesized in the liver and kidneys. Vegetarians are obviously dependent on the endogenous creatine. According to some studies, vegetarians have lower creatine levels than general population but with supplementation both vegetarians and non-vegetarians have the same levels.

Effects of creatine

Creatine is the single best known dietary supplement with several hundred clinical trials and scientific studies confirming its beneficial effects on lean muscle mass gains, strength increase and overall athletic performance.

According to most studies the performance improvement is in the range between 10% and 15%. Muscle mass gains in the first week of use are between 1 and 2 kg (about 2-4 pounds). Of course you cannot expect an increase of 2 to 4 pounds a week; this is really the first week of load. But the gains over longer periods of time are significant.

It appears from the scientific studies that subjects taking creatine monohydrate gain twice as much muscle mass over the same period of time as those using placebo. The typical period of time in such studies was 4 to 12 weeks.

How much and when

The generally established daily dose of exogenous (from external sources) creatine for athletes is 0.3 g per 1 kg of weight (or 0.14 g per 1 pound) for at least 3 days, followed by 3-5 g/day to maintain the elevated levels.

The typical creatine regimen looks like this:

Loading period: 3 to 5 days, 0.3 mg/kg of weight (0.14 mg/pound) divided into several doses taken during the day

Maintenance: 1 month, 3-5 g/day

Wash-out: 1 month, no creatine intake

The wash-out period is important – it will prevent unnecessary and possibly dangerous creatine overloading which puts strain on liver and kidneys. It will also prevent the corresponding receptors from being gradually less and less sensitive to creatine. After the wash-out period it is proper to begin with maintenance period. No loading period is required. Alternatively you can make a 1-2 days loading period but not a longer one than this.

Ideally the creatine supplements should be used about 1 hour before the workout (considering the time it takes the creatine to reach the muscle cells).

Note: Larger doses will not be absorbed in the muscles and will leave the body in urine.

Effective combinations

Some studies have shown that creatine monohydrate is more effective in combination with β-alanine. This combination was shown to produce better effects on lean muscle mass growth, strength increase and neuromuscular fatigue delay.^{1, 2}

Magnesium is necessary for conversion of creatine phosphate into ATP (this is the energy-producing process in our muscles). Some preliminary research shows that using creatine bound to magnesium in the form of Magnesium creatine may be more effective than taking the two supplements.

Creatine-glutamine-taurine: creatine is sometimes sold in this combination. Both glutamine and taurine are proven to increase muscle efficiency but it’s questionable if the three bound together really have beneficial effects.

Which creatine?

While there are several types of creatine on the dietary supplement market, only the effects of creatine monohydrate have been studied in depth.

You will often read that this or that type of creatine is “superior”, “stronger” and “most effective”. Such statements are questionable to say the least. They are usually based on assumptions, a single limited clinical trial (sometimes sponsored by the producer) or on wishful thinking.

To cite from The International Society of Sports Nutrition position stand:

“At present, creatine monohydrate is the most extensively studied and clinically effective form of creatine for use in nutritional supplements in terms of muscle uptake and ability to increase high-intensity exercise capacity.”

The same position stand also lists the following statement:

“Newer creatine formulations are more beneficial than creatine monohydrate (CM) and cause fewer side effects.”

 as one of the myths about creatine that have been refuted by scientific investigation.

You should realize – and this is the case with all dietary supplements – that a producer can claim anything about a dietary supplement and the FDA (Food and Drug Administration) must prove that such claims are not true if it wants to challenge them. Therefore the obligatory statement “These statements have not been evaluated by the FDA…etc.”

One thing that actually is important: make sure your creatine is micronized. It means the powder is ground into extremely small particles which enables much better absorption and prevents possible side-effects as diarrhea or stomach cramping.

The less studied forms of creatine include:

Creatine malate

This is a creatine bound to malic acid (Krebs cycle intermediate). It is fully water soluble and thus causes no digestive problems. Theoretically, creatine malate can provide more energy than monohydrate but this has yet to be proven.

Creatine anhydrous

Creatine anhydrous is similar to creatine monohydrate. The only difference is that anhydrous has the water molecule detached which makes it somewhat more concentrated (higher amount of pure creatine per 1 gram), the difference being about 5% to 6%.

Creatine citrate

Creatine citrate is creatine attached to a citric acid molecule. Citric acid has important role in the Krebs cycle (the energy producing pathway in the muscle cell) and it is thus speculated that the marriage of creatine and citric acid can lead to greater energy production than can be achieved with creatine alone. As with most other forms of creatine, more research is needed to confirm the underlying theory. Creatine citrate contains about 38% less pure creatine per 1 gram than creatine monohydrate.

Creatine tartrate

Creatine tartrate is creatine bound to tartaric acid molecule. This combination is not used because of some presumed benefits (as is the case with most other forms) but simply because of the stability of such combination.

Creatine phosphate

Creatine phosphate used to be pretty popular once – it was hailed as the new and improved creatine form. There is some logic behind this assumption: creatine does bind to phosphate within the muscle so here we have a ready-made form. Unfortunately the scientific studies didn’t confirm any of those assumptions: creatine phosphate molecule is simply too large to pass through the muscle cell membrane.

Creatine HMB

The HMB stands for β-hydroxy β-methylbutyrate. It is a metabolite of branched-chain α-amino acid Leucine and is proven to facilitate muscle growth and faster recovery.

The two molecules (creatine and HMB) split once in bloodstream so there is no problem with delivery through the cell membrane. On the other hand, while in the gastrointestinal tract, the two bonded molecules should be more resistant to degradation.

So far there is no sufficient research to prove the theory behind creatine HMB.

Creatine gum

Chewing gum impregnated with creatine can in theory bring two advantages: gradual release of creatine and improved absorption via sublingual route. Most producers will use creatine tartrate for such application.

Liquid creatine

Creatine in liquid form can be better absorbed and available more readily than the powder form. The problem can be if soybean oil is used as a stabilizer: we believe soy products are a no-no for male athletes.

Esterified (time-released) creatine

If there is an ester attached to creatine molecule the pure creatine will be released in the blood over certain period of time (depending on the ester used). This mechanism is often used in supplements containing vitamin C or indeed any substance that can’t be applied in higher amounts at once. Our body has usually certain threshold: it can’t absorb more than a limited amount of a substance and the rest is excreted in urine.

The question is how will this strategy work for creatine: the currently accepted administration has no serious shortcomings and gradual release may not achieve the wished-for results because there is a minimum amount of creatine needed for it to be effective. Although there are speculations that large amount administered once daily can cause the respective receptors to be less sensitive but gradual release can actually cause the same problem.

Creatine titrate

The hypothetical advantage of creatine titrate is its ability to change the pH of the water. This should enable better solubility and eventually better absorption.

Creatine ethyl ester

This esterified form of creatine has been developed by the UNeMed, the technology transfer entity of the University of Nebraska. Theoretically, it could offer much better absorption rate and longer half-life than creatine monohydrate. Scientific studies failed to confirm these assumptions and it seems that creatine ethyl ester is on the contrary less effective than monohydrate.

Effervescent creatine

Effervescent means fizzy. This form of creatine is produced by mixing bicarbonate and citric acid with creatine monohydrate (sometimes with creatine citrate). The main advantage of effervescent creatine is the stability of the solution. It is advisable to use this form of creatine if you need to prepare your energizing drink several hours before the workout.

1. Stout JR, Cramer JT, Mielke M, O'Kroy J, Torok DJ, Zoeller RF: Effects of twenty-eight days of beta-alanine and creatine monohydrate supplementation on the physical working capacity at neuromuscular fatigue threshold.

J Strength Cond Res 2006, 20:938-931

2. Hoffman J, Ramatess N, Kang J, Mangine G, Faigenbaum A, Stout J: Effect of creatine and beta-alanine supplementation on performance and endocrine responses in strength/power athletes.

Int J Sport Nutr Exerc Metab 2006, 16:430-446.

3. Willoughby DS, Rosene J: Effects of oral creatine and resistance training on myosin heavy chain expression.

Med Sci Sports Exerc 2001, 33:1674-81

4. Willoughby DS, Rosene JM: Effects of oral creatine and resistance training on myogenic regulatory factor expression.

Med Sci Sports Exerc 2003, 35:923-929.

5. Kreider RB, Almada AL, Antonio J, Broeder C, Earnest C, Greenwood M, Incledon T, Kalman DS, Kleiner SM, Leutholtz B, Lowery LM, Mendel R, Stout JR, Willoughby DS, Ziegenfuss TN: ISSN exercise & sport nutrition review: research and recommendations.

Sport Nutr Rev J 2004, 1:1-44.