But it has not previously been widely reported that he received an injection during the three-week race itself.
Some, like sickness, struck him even before the three-week race began July 5.
He said: "I had a bad day, but it's still a three-week race."
Yesterday's was the longest stage of the three-week race, 187 miles.
Asked if he could remember disappointments in the three-week race, Armstrong thought long and hard.
LeMond now trails by 6:39 with five days to go in the three-week race.
Most teams are tested in their entirety at some point during the three-week race.
Armstrong was two seconds behind, the same as last year, when he went on to win the three-week race by more than six minutes.
It will be the first time the French island has hosted a stage in the prestigious three-week race.
He has been last, or very near it, most of the rest of the time in the three-week race.
