Tour de France legend Lance Armstrong will retire from cycling after this year's showpiece in July.
The 33-year-old American, who beat testicular cancer before winning his first Tour in 1999, remains focused on adding to his record six wins in Paris.
But confirming he will then call time on a 14-year career, he said at a news conference: "Le Tour will be my last professional race - win or lose."
Tuesday's Tour of Georgia is likely to be his final race in the United States.
Armstrong, who bettered the five Tour titles of cycling greats Eddy Merckx, Jacques Anquetil, Bernard Hinault and Miguel Indurain in 2004, is cautiously optimistic about the 2005 race.
"Can I win this year? I'm not sure, but I'll try," he said.
"If I was to win it, I would be the oldest champion in modern history and my dream is to go out on top.
"We'll see if I can do it - no promises.
"But this could be a different year with Jan Ullrich looking better and a host of young riders coming up."
Armstrong admitted that he would find it difficult to stay away from cycling.
"I'll definitely have the itch to return but the decision is final - I'm 100% committed," he said.
"I still love what I do, I still go on gruelling six-hour rides.
"But I'm scared of going one race too many. All champions worry about losing - it's the fear that gets them up early."
Armstrong was only given a 40% chance of survival in 1994 after doctors discovered he had brain, lung and testicular cancer.
But he beat the odds and went on to become a global sporting icon.