The bottom line then, is that doping seems to work VERY WELL. It’s still difficult, if not impossible, to put an exact number to the benefit, though the data of Franke et al give a pretty good indication that it’s at least 15% in those power based sports. It may be slightly less for endurance based sports, like cycling. But as i wrote yesterday, there’s substantial evidence that hormone levels, particularly testosterone fall during the course of a race like the Tour. And so if Floyd Landis and others are using the drug, the benefit would come from defending this drop-off, which promotes recovery and hence allows them to maintain their form throughout the Tour. In theory then, the systematic use of drugs will have a large effect in cycling, not because it acutely boosts performance, but because it allows it to be maintained. Think of your own training – you always have good days and bad days. But what if I said that by using a drug, like testosterone, you could drastically reduce the number of bad days – that is what these drugs will do for cyclists.
In November 1942, the Italian cyclist Fausto Coppi took "seven packets of amphetamine" to beat the world hour record on the track.  In 1960, the Danish rider Knud Enemark Jensen collapsed during the 100 km team time trial at the Olympic Games in Rome and died later in hospital. The autopsy showed he had taken amphetamine and another drug, Ronicol , which dilates the blood vessels. The chairman of the Dutch cycling federation, Piet van Dijk, said of Rome that "dope – whole cartloads – [were] used in such royal quantities."