Lance Armstrong says he is behind in his preparations for a seventh straight Tour de France title tilt in July.
Armstrong is the only man to win six Tours de France
The American feels he made an error by attempting last week's Paris- Nice, which he quit after three stages.
"I'm going to try and get in shape. I have to admit I'm a little bit behind, more than I'd normally be," he said.
"I picked Paris-Nice for a lot of reasons that were decided before but perhaps I shouldn't have. It was hard, fast, intense with bad weather."
Some stages of the Paris-Nice were shortened severely due to heavy snowfall.
And that meant Armstrong - who eventually pulled out with a sore throat - had little chance to accumulate distance on his bike, so crucial to his Tour build-up.
"The body quickly wore down and got worse. Then I got sick," explained the 33-year-old, who on Tuesday was awarded France's Sports Academy Trophy in recognition of his six Tour triumphs.
"Next thing you know I go home.
"When you consider race conditions, the thing you can't emulate in training is the speed.
"When you shorten the stages by two-thirds the speed goes up and the time goes down. I was not ready for that."
However, the Team Discovery leader insists nothing will stop him from trying to win his seventh Tour "other than injury or illness or some other external problem."
He added: "I don't know that I'll win but I'll be on the start line."