"I thought it was a fair effort on his part and well within what people could expect or hope for, " said Joe Papp, a former professional cyclist who was caught doping in 2006 and suspended from the sport.

WSJ: Lance Armstrong Admits to Doping, 'One Big Lie'

"Any kind of confession is such a radical departure from Lance's past behavior, " added Mr. Papp, who became an antidoping advocate.

WSJ: Lance Armstrong Admits to Doping, 'One Big Lie'