Auckland cycle courier legend Wade Rose exists on a diet mainly consisting of muffins, cigarettes and coffee. While the effects of the first two are fairly well known; muffins provide a tasty snack and tobacco offers cancer and other nasty diseases, the effects of coffee � specifically caffeine - come under much debate.

Wade sets his daily coffee quota as, "no less than five cups, no more than 30". Although this is a fairly extreme and expensive example (at Auckland's $3-a-hit price), coffee for most cyclists goes hand-in-hand with bunch ride caf� breaks and pre-race boosters.

However, few people understand the benefits that can be gained from consuming coffee wisely or whether it is ethical or safe to consume it at all.

Until the beginning of this year, caffeine was listed on the International Olympic Committee (IOC) Banned Substances List as a stimulant. Controversially the World Anti-Doping Agency (WADA) decided to remove it along with pseudo-ephedrine. Australian cycling coach John Beasley's reaction was "ethically, it's all wrong".

To fail IOC sanctioned tests an athlete had to have consumed the equivalent of seven to eight cups of coffee in the hour leading up to the event, obviously casting doubt over any athlete testing positive who claimed to have unwittingly overdosed.

More significantly, recent scientific studies show that the maximum benefit from caffeine is achieved when athletes consume 6mg of caffeine per kilogram of body weight; approximately half the level set by the IOC as a positive test.

In addition, people metabolise caffeine at vastly different levels. A urine test might not accurately indicate the amount of caffeine an athlete has consumed. In other words, keeping caffeine on the list was virtually pointless.

According to numerous studies, using caffeine intelligently can increase sporting performance. Most concur that consuming 6mg per kilogram of body weight is the optimum amount for maximum benefit. One study even claims that over a 16km time-trial, 16 seconds can be knocked off a 21-minute ride.

Using the prescribed dosage, benefits can be gained over events as long as two hours or as short as five minutes. The Journal of Applied Science even carried out tests on the anecdotal method of filling water bottles with flat Coca Cola, finding increased performance despite its relatively small amounts of caffeine.

Some sports coaches advocating caffeine use suggest laying off for the week prior to an event, then consuming caffeine up to the magic 6mg per kg level shortly before competing.

There is, in fact, no evidence to prove that laying off caffeine and then reintroducing it has any enhanced effect. Additionally, caffeine consumed during exercise does not increase urinal flow. The guy in the bunch rides who dashes behind the nearest tree every 10km isn't necessarily a coffee junky, more likely just a lad with a weak bladder.

When coffee was introduced to the western world via Turkey in the 16th Century, anti-coffee movements and protests sprung up almost as quickly as coffee houses themselves. Most objections centred on the apparent decline in libido among men frequenting coffee bars, leading to a common myth that coffee caused impotence.

Some medical practitioners supported this view, although coffee was also attributed to drying of the liver, effeminacy and even paralysis. These somewhat frightening side effects are now largely dismissed but caffeine can cause headaches, seizures and nervous irritability.

It is common for regular users to experience withdrawal symptoms should they be unable to get hold of their usual fix.

Using caffeine safely and intelligently to gain a sporting advantage surely prompts an ethical question. If an athlete is consuming a non-traditional nutrient such as caffeine to aid his performance, doesn't that constitute doping?

If so, sports agencies find themselves in a quandary such as WADA did; unable to effectively enforce a ban. This situation is not unusual and the problem can be compared with the UCI's method of testing haemocrit levels in the 1990s rather than for EPO itself. This resulted in riders with 'non-negative' tests and 'advised' not to race as opposed to being positive and banned.

British multisport coach Joe Beer says, "as it is not banned it is wrong to call it a drug".

"It is a perfectly legal ergogenic aid, like training, lightweight shoes, aerowheels or a heart rate monitor."

Surely by this argument, using any performance enhancing substance is fine as long as it is not on the list, certain kinds of horse testosterone, for example?

On the other hand, an Australian mens' under 21-cycling coach argued, "these products (caffeine and ephedrine) are performance enhancing, end of story".

In essence the whole debate is one big grey area, denser than a foggy day in London.

Caffeine's defence is that it is the most widely used psychotropic drug worldwide. It is found in products from coffee to chocolate and most of us consume it regularly as part of our daily routine. Besides, what would motivate bunch rides other than a coffee stop, and what would get Wade Rose through the day other than his 15th long black?