The Tour de France, which kicks off July 5, is a grueling test of human endurance, a three-week 3,500km racestretched over 21 stages, nine of them in the mountains. But in some ways the modern Tour is easier than races past. Inthe early 20th century, competitors pedaled the dirt roads of France through the night on fixed-gear bikes, evadinghuman blockades, route-jamming cars and nails placed on the road by fans of other riders. Between stages, teamsfeasted on banquets and champagne; before climbs, they fortified with cigarettes.        

    The race was the brainchild of Henri Desgrange, a Parisian magazine editor who launched it in 1903 with 60riders in a bid to boost circulation. It worked: Tour coverage helped Desgrange’s magazine boom, and the race soonbecame more popular than he could have dreamed. With fans lining the roads to see riders up close, by the 1920s theTour included more than 100 cyclists from throughout Europe. But as the competition grew fiercer and the race morecommercialized, champagne and nicotine gave way to more effective—and insidious—performance boosters. In 1967,British rider Tom Simpson died midrace after taking amphetamines, prompting the event to adopt drug-testing. In 1998, authorities disqualified the Festina team after finding the red blood cell-boosting drug EPO in their car. Thewinner of the 1996 race, Bjarne Riis, admitted in 2007 that he had used EPO, just months before Floyd Landis becamethe first Tour winner stripped of his title on charges of using synthetic testosterone in 2006. The Tour now tests athletesrigorously—stage winners are screened daily—although the victor in this year’s race will still be allowed a sip ofchampagne.