ATHLETICS:OF ALL the naively thought out and innocently-motivated and foolishly-experimental mistakes of my short and completely undistinguished running career, downing a four-shot espresso - aka an "Ambulance Chaser" - right before an indoor 3,000 metres race was perhaps the most damaging, at least potentially so.

Not only was it the beginning of a now hopeless addiction to caffeine, but if the drug-testers happened to be about that day then my sample may well have produced an Adverse Analytical Finding.

Whatever competitive edge the caffeine was meant to offer was probably lost by the rapid onset of acute dehydration and severe palpitations of the heart. It definitely wasn't one of my better races. But back then caffeine was prominently placed on the list of banned substances, and there was no such thing either as a Therapeutic Use Exemption. It could so easily have been a guiltless but shameful drugs bust.

When the World Anti-Doping Agency (Wada) came together in 1999 - the new chiefs of police in the worldwide crackdown on drugs in sport - one of the things they did was take caffeine off the list of banned substances. Wada decided there was no definite evidence that caffeine offered any performance-enhancing properties, and instead was more likely to be performance-decreasing above the threshold that was previously used to determine a positive sample. Amen to that.

This was one small step towards clearing up that grey between what is considered to be a performance-enhancing substance and what is not. But if any athlete out there is running a little more scared this week as a result of a certain Gaelic footballer innocently and inadvertently testing positive for something as harmless as his asthma medicine then they had better read on - because this situation is only going to get worse. They may be able to wake up and smell the coffee, but they may yet need to be careful about what they do in bed.

Just yesterday, the Irish Sports Council published its revised anti-doping rules, effectively to mirror the similarly revised rules of Wada, which come into effect on January 1st. The news is mostly good as it broadens the spectrum of anti-doping violations that can lead to a four-year suspension, such as using multiple banned substances, or using a banned substance on multiple occasions.

There is also a new whereabouts requirement which makes athletes more accountable for their availability for testing, plus an amended right for the testers to collect samples for the purpose of biological profiling, or to reanalyse samples where appropriate. (In other words, to test for banned substances later which they're not able to test for now.)

The bad news is that the Therapeutic Use Exemption - which give athletes permission to use certain substances such as salbutamol, the main ingredient in asthma medication, which otherwise would return a positive sample - is being tightened up considerably, and from now on all such exemptions will require a significantly higher level of medical detail.

And that's only for now. If Wada have their way, another substance which may require a therapeutic exemption is sildenafil citrate - more popularly known as Viagra. Believe it or not, there is an increasing amount of anecdotal evidence to suggest that Viagra is being used by some athletes to gain an advantage over their competitors, and Wada are taking a good look at it. The problem here, it would seem, is a very definite case of unfairly stimulated performance.

So concerned are Wada about the potential benefits of Viagra - beyond the intended medical benefits, obviously - that they are funding three separate research projects to help determine if they should add it to their banned list. The University of Miami, Tufts University and Marywood University in Pennsylvania are at an advance stage of these projects and the entire sporting world is eager to know what they come up with.

The Marywood researchers are looking at how Viagra could help athletes cope with air pollution as well as its effect on increasing performance at mild altitude, and will provide Wada with their results before the end of the year. The expectation is that Wada will then add sildenafil citrate to its list of banned substances, requiring a Therapeutic Use Exemption, when it revises its anti-doping rules for 2010.

All this isn't based on some hunch or a tip-off from the porn industry. According to Christiane Ayotte, head of a Wada-accredited laboratory in Montreal, there has been a highly suspicious increase in traces of Viagra and also Cialis, a similar product, in the urine of male sports competitors. Of course Wada can't do anything about it because it's not currently illegal.

"Each time there is a seizure of banned drugs you can be sure that there's Viagra and Cialis found as well," sais Ayotte, and the obvious assumption is that it's not all intended to treat erectile dysfunction. American doping expert Don Catlin also said hat had suggested several years ago that Viagra could be used to enhance athletic performance, and that it should be put on the Wada banned list.

But who better than Victor Conte of Balco fame to describe in intimate detail the potential benefits of Viagra for the unscrupulous athlete. Conte claims that back in his more deceitful days he regularly supplied his athletes with Viagra or similar products in 25-miligram doses, to be taken along with the blood-booster EPO.

"Oxygen is transported into the heart to be pumped out to rest of the body," explained Conte. "Viagra widens the lungs and pulmonary arteries. This is where the exchange of carbon dioxide and oxygen occurs. So more red blood cells carrying oxygen get into the heart and more carbon dioxide is pumped out."

If Viagra - or Vitamin V, as it's now known in doping circles - does have any performance enhancing qualities outside of the bedroom then you'd expect cyclists to be onto it, and it seems they are. Back in May, Andrea Moletta was kicked out of the Giro d'Italia when national police searched his father's car and found 82 Viagra pills and a syringe. But Moletta wasn't suspended because again he hadn't broken any rules.

Even if it doesn't offer any definite benefit in sport, Viagra is also suspected as being used to counteract the impotence that can be a side-effect of testosterone injections, and that may well be enough reason for Wada to ban it.

The biggest potential problem with all of this is the Therapeutic Use Exemption, because some athletes, unfortunately, have a genuine need for Viagra. Proving this to Wada may not only be difficult but also embarrassing, because as anyone who has ever used Viagra could tell you, it won't cause an erection without stimulation.