If you've been working long and hard in the gym but find that it's weeks or months since you saw any appreciable gains in strength or muscularity, you may well get used to hearing that these sticking points are entirely normal and that there's no alternative to working ever harder until your body somehow miraculously trains its way through the problem.

But unfortunately when it comes to activities such as lifting weights, body-building, field athletics, sprinting or contact sports, the idea that ?more is better? simply doesn't work. The problem is that the stronger you get, the more intensively you need to train to maintain your progress, placing huge demands on the energy reserves in your muscles and your body's powers of recovery.

So this can be an intensely frustrating time. Your progress has inevitably slowed, yet if you try to force the pace beyond your body's recovery ability you risk ceasing to progress altogether, and may even find yourself getting weaker.

Not surprisingly then, strength and power event athletes have searched desperately for anything that might help them get past this barrier ? even turning in large numbers to the illegal and highly dangerous, but often extremely effective anabolic steroids. But those sensible enough on grounds of ethics or self-preservation not to go down this route needed something else.

The isolation of creatine, a 100% natural substance that seemed to mimic the effects of steroids therefore produced enormous excitement. While even now the science behind creatine remains to some extent in its infancy, the key to its importance seems to lie in its relationship with another compound in your body called adenosine-tri-phosphate (ATP), which is the vital source of energy your muscles need when engaged in an intensive, quick burst activity such as lifting weights or sprinting.

The problem is that in most people supplies of ATP are exhausted as quickly as within 10-15 seconds, to be replaced by the useless by-product, adenosine-bi-phosphate (ADP). Amazingly enough, it seems that the creatine stored within your muscles can then convert the ADP produced by this process back into ATP, producing more energy for your muscles, rather in the way that a car turbocharger works.

More energy in your muscles means the ability to perform longer, harder workouts, which can't help but dramatically accelerate your gains in greater strength and power ? always provided of course that you allow adequate time for recovery. And although less well understood, there is evidence that creatine can enhance the process of protein synthesis by which your body repairs and strengthens muscle tissue, potentially reducing the necessary recovery time between workouts.

Creatine is produced in the liver by the synthesis of three essential amino acids ? arginine, methionine and glycine and around 95-98% of your body's supply is stored in the muscles ? typically in a concentration of around 3.5-4 grams per kilogram of bodyweight.

So the crucial question was: would supplementing these natural levels enhance creatine's effects? When research indicated that the answer to this question was yes, it was no surprise that creatine quickly became the biggest selling sports supplement of all time. In fact as long ago as 1988 more than $200 million worth of creatine products were sold.

But a couple of cautionary words are necessary. Some of the marketing behind this astonishing figure has been ethically dubious to put it politely. It has to be stated that creatine is definitely not some miracle formula for superhuman strength. You're not going to be able to pop a pill and sit back on the couch with a pizza while your body quickly and painlessly transforms itself into that of an elite strength athlete.

Creatine may dramatically enhance the results of your workouts, but in no way can it be a substitute for them. If you want the results, you still have to put in the work, a point by the way, which is often forgotten, but equally true of anabolic steroids.

Secondly, creatine seems only to be really effective for certain kinds of physical activity; those which demand muscle strength, bulk and explosive power. The benefits have proved much harder to assess in the case of endurance events such as long distance running, swimming cycling or triathlon, although there is some evidence that creatine may help in slowing down or reducing the build up of lactic acid, the substance that causes that characteristic and painful burning sensation as your muscles fatigue during exercise.

Remember, too, that creatine occurs naturally within the body, and as with other such substances the amounts vary from individual to individual. So understand that if you're one of those who naturally produce high levels, further supplementation may produce little or no benefit. Conversely, if your body produces only moderate to low amounts, a good quality supplement may well produce very rapid developments in your physique.

The only real way to tell which category your body falls into is to give it a test drive with this new muscle fuel supplement. A month of supplementation, combined of course with regular tough workouts, should be enough to find out whether creatine's going to help you.