Creatine

Much is said about creatine, but what's the real utilisation by the body?

Creatine is an energy rich metabolite found mostly in muscle. Creatine phosphate is replenished at rest and is then available to phosphorylate ADP to ATP facilitating energy production. This mechanism is a very rapid energy production, but of very limited concentration and duration. Glycolysis (sugar burning) is the next fastest and lastly the fat burning aerobic mode. Anaerobic exercise quickly uses up creatine and then falls to carbohydrate utilisation, but exhaustion sets in as there is not enough energy to sustain the output requirement. Creatine supplementation does not assist endurance performance, but can help in the high output type work. Also, fatigue onset is not so early. Better performance can be produced with creatine supplementation compared to placebo.

However, after short intense exercise, the better performance is not sustained. It may be that a slightly reduced intensity may allow longer duration exercise, but longer rest is required between repetitive sets to benefit. The more creatine then the faster the recovery and the creatine system spares glycogen. Overall, creatine supplementation allows harder training and may thus improve muscle growth. Bulk and weight gains are mostly water retention. A muscle wasting condition known as gyrate atrophy involves a defective creatine synthesis. This is reduced by low-dose, long-term supplementation. It is not clear if healthy individuals would similarly benefit.

Vegetarians show the greatest improvement and as the creatine levels are normally lower an additional boost is not surprising. Creatine is synthesized from arginine, methionine and glycine although high levels of these three amino acids does not translate into more creatine. If the level of creatine can be boosted above the normal diet level by supplementation then there will be a benefit. Creatine is stored chiefly in fast-twitch fibres. Those with a high proportion of these fibres can lead to levels of up to 50% higher than normal. The upper limit of supplementation is generally around 0.3g/kg per day and is reduced after 6 days to 0.03g/kg (ie 10% level).

The duration of enhanced levels is not stated, but there is a finite storage time. Warm or cold water is used to introduce creatine supplements, though hot water destroys creatine. Creatine can improve a properly structured training regimen, but otherwise it is useless. The anaerobic creatine system is allowed to continue, but only for a shorter time. Minutes. Almost certainly, there are new methods of training since synthetic creatine is now available. Simply to have higher levels than through normal diet. It should be noted that creatine supplementation can improve recovery rate, decrease fatigue and enhance protein synthesis.