That all seemed unlikely before this week, especially after Armstrong crashed in March and broke his collarbone, the first serious injury in a 20-year career. And it was widely known that in retirement, he partied, dated celebrities and enjoyed life outside the strict confines of cycling training in which it is necessary to measure food portions and heart and lung capacity daily.
"This is a 37-year-old cyclist competing in, by far, the toughest race ever, and he's come out in the first week and done things that are absolutely ridiculous, stunning," said Sean Petty of USA Cycling. "I think it shows that you can never, ever take Lance for granted.
"If he were to win this I think it would, in its way, be more spectacular than what he accomplished winning seven."
Today's nearly 140-mile stage will be the first serious test of Armstrong's climbing fitness. The stage leaves Barcelona, meanders into the Pyrenees and finishes at about 7,300 feet. It is made, according to the Tour de France guide, for "the bold, sturdy climber who breaks away from the pack early to seize his chance."
Sunday's stage is even tougher, 99 miles of up and down, across two historic Pyrenees passes at Aspin and Tourmalet.
"He came into the Tour lighter than he's ever been," said Chris Carmichael, Armstrong's longtime trainer. "All his numbers that indicate endurance and strength are better than ever. What we need to see now is whether his climbing legs are there."
The race, however, may not be decided until the final climb on July 25 up Mt. Ventoux, a wind-swept, broiling hot, rocky summit where British cyclist Tim Simpson died climbing in 1967.
"I think this race will go down to Ventoux," Hincapie said. "And Lance will be there."