Better technology and stricter rules have made egregious doping harder.In Tokyo, samples will be analysed by sophisticated chromatography to look for drugs or their metabolites.Biological passports will be scrutinised for indirect evidence of blood doping, which may reveal itself as suspicious changes in any of a dozen variables,including levels of haemoglobin (the oxygen-carrying molecule that gives blood its red colour), red-blood-cell count, and the proportion of those cells which are immature.Outside competitions, "whereabouts" rules mean elite athletes must keep antidoping authorities apprised of their movements, to permit unannounced tests.But record performances are not necessary for victory. Simply being better than your opponents on the day is enough.For that reason, subtler chemical assistance is still worth pursuing.One option is to experiment with new drugs.Sometimes, these are created deliberately to dodge the tests.In 2003 a syringe was posted anonymously to American anti-doping officials.It contained a new AAS nicknamed "The Clear", for which no test existed.This had been developed by a chemist called Patrick Arnold and supplied to athletes including Marion Jones, an American sprinter with a string of Olympic medals to her name, who admitted using it.Most new drugs, though, are created by the pharmaceutical industry.
