For as long as there's been sports people have been using ergogenic aids of the permitted and non-permitted types in an attempt to improve their performances. This means that for as long as people have been racing bikes people have been doing this. What changed over history is the sophistication of the techniques used, and this has mirrored scientific and pharmaceutical developments over the years. Early 20th-century doping was primitive - "brandy and strychnine" having been famously used by an early marathon winner at the modern Olympics, and for most of the century simple stimulants and amphetamines were routinely used. Bike racing was and still is, hard, and back then distances raced were far greater, bikes were heavier and equipment was poorer. People would take whatever they could just to get to the finish. Later, the focus moved to the newly-developed anabolic steroids, blood transfusions and "blood boosters" such as the current media darlings EPO and CERA, and along with it the focus of doping moved from "get through this race" to organized medium-term programmes of planned doping arranged to produce the right result in a race that might still be weeks or months away. This is why random testing now happens out of competition as well as after races.Cycling doping's past and a new start
Once in 1910, when French rider (and eventual winner) Octave Lapize passed some Tour de France officials on the brutal climb up the Col de Tourmalet, he yelled out to them:
"Vous etes assassins!" You are murderers!
The idea of the Tour de France came from a couple of French newspaper guys sitting around drinking. They imagined the most difficult bike race possible, and then they made it happen.
Before drug testing, it was common for riders to use alcohol, pain killers (up to and including heroin), amphetamines...anything they could get their hands on to keep themselves going on a ridiculously tough ride around France on one-speed, 40-pound bikes (today's pro bikes weight about 15 pounds). The doping culture of cycling comes down to today's athletes through the legacy of the earlier years of professional cycling. Five-time Tour de France winner Jacques Anquetil openly admitted to doping in the 1950s and 60s.Cycling doping's past and a new start
Organized doping probably reached its zenith in the 1960s and 70s, when it was an open secret that entire teams in many sports at the Olympics were on complicated doping regimes. Doping was also used systematically by some national sports academies (mostly in the former Soviet bloc).
Then the cycling community seemed to stand up and take notice when, during the 1967 Tour, British rider Tom Simpson collapsed and died while climbing Mont Ventoux. He had alcohol and amphetamine in his system. Since then, doping and testing have gone through many changes--usually, the testers trying to keep up with the dopers unsuccessfully. Only in the last couple years has the sport really started to get clean.
Even as recent as Lance Armstrong's era in the 1990s and 2000s, doping was far, far more rampant than it is now. What many pros of the time have said is that they didn't feel they had a choice if they wanted to compete (because everyone else was doping, which could easily have been true).
In more recent years, two things have changed - firstly, the testing and penalties have got far more serious along with the quality of testing improving, and secondly, there's been an enormous cultural shift away from the 'nod and wink' attitude of the past that prevailed both among participants and the public. Cyclists who are found to have doped are not popular among the rest of the peloton even if they do return after a ban - not least because every high-profile doping case puts every pro cyclist's job at risk as sponsors threaten to pull out.Cycling doping's past and a new start
The tests including Biological Passport tests have improved and the culture of professional cycling is changing. Besides, there's been a cultural shift in cycling and new teams that stress a clean culture. Like Garmin-Sharp led by Jonathan Vaughters (a former pro and anti-doping activist, who has admitted to doping during his own career because of the pressure to succeed).
The most unsettling aspect of doping in cycling isn't the doping itself, but the rabid insistence of pro cyclists and others involved in the sport that they're clean. With these new teams and a cultural shift away from doping, along with more advanced testing (still needs work) and more data collecting (the biological passport maps an athlete's natural blood hematological profile), many of today's pro cyclists have said they don't feel the pressure to dope anymore. The consensus is towards clean racing, and that the major teams are following a no tolerance policy.