Creatine is often one of the things that runners discuss when thinking of ways to get an "edge" on the opposition. It is one of the supplements where there does appear to be a significant physiological effect to taking it.

However, before even thinking about how to take it you should know what it might do for you and about the possible side effects.

Starting from the beginning - creatine is used by the body (specifically, muscles) to form phosphocreatine or creatine phosphate. This then combines with ADP to form ATP, which is the source of energy we use for short-term energy production (the energy is released when ATP is split).

ATP as an energy source lasts only 3-5 seconds, after which we have enough creatine in our muscles to provide another 10 seconds or so of high intensity energy source for power exercises. It has been shown that supplementation can increase this store by up to 50%. Note the "up to" as this can range from 0% - 50%. Note the "up to" as tihs can range from 0%-50%. Around 20% of people are ‘non-responders’ to creatine supplementation, demonstrating no increase in creatine stores. In contrast, others display significant increases, particularly in those who initially have very low creatine stores such as vegetarians.

Photo Sprinters can benefit from creatine in many cases

When a bout of exercise is beyond this range we get our energy from the release of energy given when carbohydrates, fats and oxygen react together. Therefore, in theory creatine is no use when we are using these energy systems.

However, recent studies at Texas A&M University have shown that creatine supplementation may decrease the production of lactate by the body - which theoretically would increase the lactate threshold of an athlete and therefore improve performance. However, other studies have shown no benefit to long distance runners.

Side effects

There haven't been a lot of studies carried out into the side effects of creatine supplementation. Generally, it is thought to be relatively safe, but a couple of observations have been made. Firstly, it can cause dehydration - leading to cramps - so those taking it should increase their water intake on a daily basis.

It typically leads to a mean increase in body mass due to increased fluid retention as creatine is a large molecule which draws in excess water by osmosis. This can mean it is not always beneficial to sprint performance. It can also lead to increased frequency of muscle cramps.

More seriously, no long-term studies have been undertaken into its effects, and the most major concern is the long-term effect on kidneys and liver. There is a suspicion that damage could well be caused to these organs by prolonged use of creatine, but we don't know. A few cases have been reported as possible deaths from its use, but there haven't been widespread problems - which is clearly a good thing and it has been available as a supplement for over 30 years now, so we'd have expected to see serious problems occur already if they did exist.. Overall, you need to be sure that the benefits of putting this substance in your body outweigh the risks.

Who might benefit?

So, assuming the risks are acceptable - who might benefit from creatine supplementation.

Basically, working on the theory above, anyone involved in high intensity exercise over short durations (up to 20 seconds) of time.

If you do plan on supplementing with creatine it has been recommended to be taken in two ways - firstly taken in a loading phase to increase total creatine levels before reducing supplementation to a maintenance dosage to preserve the higher levels and then a period without taking any. However, more recently it has been recommended that smaller amounts are taken consistently. Currently, we'd recommend the latter from what we've seen although it is perfectly possible that either could be best and may vary by individual. For best results it is taken with carbohydrates whilst caffeine can diminish its effects.

Photo Athletes may want to time creatine consumption with races

This may well include more than just power athletes - as many middle and long distance runners include weights and sprints in their training programs.

The information here is written by athletics coaches who have read widely into the subject and not a sports nutritionist, so is about gearing your food and drink to the practicalities of running.

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