Anti-doping triumph certain
IN THE last five years, anti-doping in sport has been transformed as a result of a paradigm shift in the way authorities approach the challenge of catching cheats who use illegal substances to find an edge.
Historically, anti-doping authorities invested time and money looking for the presence of a banned drug in the blood or urine sample of an athlete.
Be it a steroid like Ben Johnson used, a performance-enhancing hormone like EPO, or a stimulant, the classic approach to doping was to detect the illegal substance, and then ban the athlete.
In hindsight, we were naïve to hope that this "smoking gun" method of doping control would be effective. Athletes are too clever and doping is too complex to police in this manner.
Too many substances cannot be detected, the effects of drugs continue long after the drug has disappeared from the body, and athletes can creatively avoid testing when they know it is coming.
This is why the 5000 tests that will be done in London, impressive as they are, are only a small part of the ongoing battle.
What if there was a method that allowed authorities to tell whether an athlete had doped long after the banned substance was gone? What if the authorities could detect doping not by finding the illegal substance per se, but by tracking how an athlete's physiology changed in response to that drug?
Enter the biological passport system. This concept, the newest weapon in the fight against doping, was first introduced for cross-country skiing and cycling about five years ago. It aims to track the effect of doping, rather than the actual drug itself.
The analogy is that on a road-trip from Johannesburg to Cape Town, authorities can nab speeding motorists by placing cameras at regular intervals in the hope that they catch you at that exact moment that you are speeding. But once you know where the cameras are, you can slow down just in time, and then speed until the next camera.
In the world of anti-doping, the cameras are drug tests during competition, and athletes know when they are coming and so they simply stop using the drug long enough to evade detection.
But let us say the authorities move away from this camera approach, and instead use a method that measures how long a car has taken to get from Point A to Point B along the journey. If you arrive at Point B faster than the speed limit would allow, then authorities would not need to literally catch you speeding to know that you have broken the law.
In the same way, scientists use a biological passport to track each athlete's unique blood physiology over the course of many seasons. They test blood frequently, looking for changes in its composition.
This includes red blood cell levels and haemoglobin, which are both vital to carry oxygen, and which rise or fall with EPO use or blood doping. If an athlete's values change in unnaturally large amounts, then authorities can infer doping, having never actually detected the drug.
So far, the signs are encouraging. Almost overnight, the number of suspicious blood samples in professional cycling was cut by 90%, and the average red blood mass and haemoglobin levels of professional cyclists suddenly dropped.
But performances were affected - the sport got slower almost instantly. The reality is that the cyclists are "scared" of the passport, because they know that its fundamental concept - detecting the change and not the drug - means there are fewer places to hide.
Other sports have followed suit - athletics introduced its passport last year, and it too has caught a few athletes. The war on doping will probably never end, and the reality is that even the most sophisticated, intensive and expensive testing in the world will not eradicate doping, but the race is more competitive now than ever. Thanks to the biological passport.
Tucker is a research scientist at UCT's Sports Science Institute. His column on the Olympics will appear every Wednesday until the conclusion of the Games. Follow Tucker on twitter @scienceofsport