AS the Tour de France sets off from Le Puy du Fou this afternoon, there was yet another reminder this week of the harmful side-effects of a life in the peloton.

According to a scientific study published in the weekly French magazine Nouvel Observateur, professional cyclists are five times more likely to die prematurely than ordinary members of the public. Of the ,2363 professional cyclists aged between 25 and 34 years interviewed for the survey, 238 have since died. The main causes of death were cancer (79), heart disease (67) and road accidents (58).

The survey concluded that the high mortality rate could only be explained by the use of drugs by professional cyclists and in particular the elaborate masking techniques used to avoid detection. Those fears, however, will hardly be enough to halt the continued experimentation. French champion Laurent Jalabert, who refused to ride the Tour, was the latest to admit this week that "there is a problem in the biological preparation that unfortunately leads to doping".