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home  |  health information  |  health living  |  lifestyle  |  exercise

Creatine and the athlete

What is creatine?

Visit any health food store or browse through a sports magazine and you'll probably come across creatine and, in particular, creatine supplements. But what is it and what does it do?

Creatine is produced naturally by the body and helps to improve muscles' performance during exercise. This improvement in performance should allow you to train at higher levels for certain sports and gain muscle.

Foods such as meat and fish provide much of the body's creatine and the rest is made in the body by the liver, kidneys and pancreas. It is stored in the muscles as phosphocreatine (you may find it referred to as PC) contributing to the body's energy stores used during intense exercise.

Why take creatine supplements?

Increasing the muscle stores of phosphocreatine by taking a creatine supplement theoretically improves the ability to maintain power output during intensive exercise. It is also thought to aid recovery between short bursts of activity. This effect could benefit your training programme and provide an important edge when competing.

Taking creatine supplements can increase your muscle stores of phosphocreatine by roughly 20 per cent on average. However, the exact increase can vary depending on the individual - the range is somewhere between 10 per cent and 40 per cent.1

Increasing your muscle stores of creatine is particularly beneficial if you are involved in sports that involve short bursts of intense exercise. It can also help you maintain higher training volumes.

Creatine and different types of physical performance

Evidence suggests that creatine supplementation is probably more useful for those sports whose activities require a good anaerobic performance.2 Such activities include weight lifting, sprinting, football and rugby. There have been many studies to examine its effect in this area and over half of these have shown quite positive outcomes. Therefore, for those athletes whose sport requires strength combined with intense activity, this supplement could help.

However, for sports requiring mainly aerobic performance there is less evidence that creatine supplementation is helpful. So, for the endurance athletes - such as runners, cyclists and long distance swimmers - the case is not so strong. Nevertheless, a few studies have shown some improvement in performance.3 For example, a study at Louisiana State University found that creatine supplements delayed the onset of muscle fatigue in endurance athletes by boosting their lactate thresholds.4 So, for some aerobic sports, it may be useful.

Will taking creatine supplements alter my body weight or body composition?

Studies have shown that creatine supplementation does increase body weight and also has an effect on body composition.5,6 In particular it increases muscle mass and this effect has been found in both male and female athletes. Weight increases of up to 4kg have been reported after a period of six weeks with creatine supplementation.

It is thought that this weight gain occurs because increases in the concentration of creatine in the muscles has the effect of drawing water into the muscle cells, thus increasing cell volume. This increase in volume acts as an anabolic signal which helps to reduce protein breakdown and improves the body's usage of protein. The end result is an increase in lean body tissue.

What's the best way to supplement the diet with creatine?

The most extensively used form of supplement is creatine monohydrate. It is a white powder which is almost tasteless and dissolves in water. Ideally, creatine should be taken together with some carbohydrate-rich food. This is because the carbohydrate increases the concentration of insulin in the blood stream which, in turn, helps the creatine to be absorbed by the muscle cells. A snack containing between 30g to 40g of carbohydrate is ideal for this purpose. For example, a banana, two thick slices of wholemeal bread, or a bowl of muesli.

There are other forms of creatine. For example, creatine phosphate and creatine citrate. However, these are not absorbed any more readily and are also more expensive.

How much should I take?

As far as the dosage of creatine is concerned, there are a number of different recommendations. There are no Recommended Daily Amounts (RDAs) for creatine as such. However, most manufacturers suggest starting off with a loading dose of about 20g per day for five days. After this initial period, follow up with a "maintenance" dose of around 2g per day on an ongoing basis. There is no benefit in taking a higher dose since muscles have a maximum storage capacity and any excess is simply lost from the body.

Is creatine supplementation safe and are there any side effects?

Studies so far have not highlighted any problems.7,8 If you are training and taking creatine supplements you will almost certainly gain weight, particularly lean body mass. Creatine supplementation is not illegal and is allowed by the International Olympic Committee.

Key points

  • Creatine monohydrate is the most widely used form of creatine supplement
  • Creatine is made up of three amino acids and is stored as phosphocreatine in muscles
  • Creatine delays muscle fatigue by "buffering" the build up of lactic acid in the muscles
  • It speeds up recovery between bouts of high-intensity physical activity
  • It extends maximal muscle power output
  • It increases total body mass - particularly lean muscle tissue
  • May be especially beneficial to athletes involved in high-intensity activities particularly where interval training and strength training are involved i.e. anaerobic activities
  • There is a small amount of evidence that it may also help athletes involved in mainly aerobic activities - for example endurance running and cycling - although the evidence is not strong
  • Dosage - there are a variety of recommendations, however the most widely used is a loading dose of 20g per day for five days, followed by a maintenance dose of 2g per day. Doses in excess of this are of no benefit as muscle can only store a certain amount and any excess is removed from the body
  • Side-effects - there appear to be no proven side-effects
  • Creatine supplementation is allowed in sport by the International Olympic Committee (2002)

References

  1. Hultman E et al. Muscle creatine loading in man. J Appl Physiol 1996; 81: 232-7.
  2. Volek JS, Kramer WJ. Creatine supplementation: its effects on human muscular performance and body composition. J Strength Cond Res 1996; 10(3): 200-10.
  3. Nelson A et al. Creatine supplementation raises anaerobic threshold. FASEB J 1997; 11: A586 (abstract)
  4. Prevost MC, Nelson AG, Morris GS. Creatine supplementation enhances intermittent work performance. Res Q Exerc Sport 1997; 68(3): 233-40
  5. Kreider R et al. Effects of ingesting supplements designed to promote lean tissue accretion on body composition during resistance training. Int J Sport Nutr 1996; 6: 234-46.
  6. Clark JF. Creatine and phosphocreatine: A review. J Athletic Training 1997; 32: 45-50.
  7. Williams MH et al. (1999). Creatine: The Power Supplement. (Illinois; Human Kinetics).
  8. Poortmans JR, Francaux M. Long term oral creatine supplementation does not impair renal function in healthy athletes. Med Sci Sports Ex 1999; 31: 1108-10.

 
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