nLance Armstrong is now the front-runner in the Tour de France -- but that doesn't mean he's at the top of his game.
Despite clinching the overall leader's yellow jersey for the first time after finishing third in Sunday's sun-drenched Alpine climb, the Texan has concerns about his form.
"I'm perhaps not as strong as in previous years," Armstrong acknowledged after Sunday's eighth stage -- a 219km mountain slog won by Spain's Iban Mayo.
With another punishing mountain ascent Monday and four more later in the Pyrenees, the four-time champion remains the favorite -- but not necessarily an overwhelming one.
"I didn't have the greatest sensation, the greatest legs today," the 31-year-old cancer survivor said. "Let's hope things get better and not worse."
A chink in the armor? Possibly, because Armstrong is nothing if not a straight talker.
"It was no bluff today, it was a tough, long day," he said.
Armstrong, who devoured the notorious L'Alpe d'Huez -- and his opponents -- in 2001, found the same climb more of a foe than a friend Sunday.
"If you'd asked me a month ago are you going to suffer like that on L'Alpe d'Huez I would have said No way!" he said. "I had some issues at the start of the Tour that weren't ideal for coming into the race."
Those issues included a bout of gastroenteritis that had upset his Tour preparations, according to Jogi Muller, the team's spokesman. Although Armstrong said he is feeling "better," he is not exactly sounding the battle cry either.
In today's ninth stage, a 184.5km trek from Bourg d'Oisans to Gap, Armstrong may face adversity on two fronts.
Rivals now know he is vulnerable to unanticipated attacks -- Sunday's performance showed that even he can be ruffled -- and he must keep his racing sense in tact to negotiate two climbs exceeding 2,000m.
These include the Col d'Izoard, which stands at an imperious 2,360m.
Looking ahead from Monday, Armstrong will have a relatively flat stage Tuesday, ending in the seaport of Marseille, and a rest day Wednesday.
An individual, 47km, time-trial Friday leads into four days of Pyrenees climbs -- considered as difficult as their Alpine counterparts.
Armstrong is fast enough to make up any deficit -- should he be overtaken before Friday -- in a time-trial. Yet he may need to go doubly quick in order to bank some time-in-hand for the grueling Pyrenees.
In Sunday's eighth stage, Armstrong couldn't match Mayo's infernal pace in the legendary L'Alpe d'Huez climb.
Mayo dominated the duel to win in 5 hours, 57 minutes, 30 seconds. Kazakhstan rider Alexandre Vinokourov placed second, 1:45 behind Mayo. Armstrong, who accepted he'd ``definitely'' attacked too early, finished 2:12 behind the winner.
The stage, which started in Sallanches, included the awesome Col du Galibier, which towers at 2,645m.
"It was a really hard stage from the start," Armstrong said. "The whole pack attacked."
Armstrong failed to shake one of his key rivals, Joseba Beloki of Spain, on the final 13.8km battle to the finish line at L'Alpe d'Huez.
"The attack by Beloki was very strong," Armstrong said.
After Sunday's stage, Beloki was in second place overall, 40 seconds behind Armstrong. Mayo was third, 1:10 behind.
"A dream has become reality," Mayo said. "L'Alpe d'Huez is a mythic stage."
Armstrong criticized one of his teammates, Manuel Beltran, for some of his difficulties up the final ascent. Beltran, a newcomer to Armstrong's US Postal Service squad, charged off at a fast pace, hoping to help Armstrong shake off his rivals.