By Julian Linden
NEW YORK (Reuters) - The clock is starting to tick faster for Michael Phelps. The London Olympics are drawing closer and the American swimmer knows that time is running out on his golden career.
Not so long ago, Phelps was measuring the countdown to his final Olympic appearance in years. Then it was months, then weeks. Now it is days.
"Not long now, it's less than 170 days now," he told Reuters during a visit to New York City for the global launch of Head and Shoulders' "Wash In Confidence" campaign.
For Phelps, the countdown will soon come down to hours then minutes, although his success will ultimately be judged by fractions of seconds.
In the world of Olympic swimming, gold medals can be decided by margins as tiny as a fingernail, and no one knows that better than Phelps, who won a record eight gold medals at the 2008 Beijing Olympics after surviving two close calls.
Phelps was a member of the U.S. relay that won the 4x100 meter freestyle final by just 0.08 seconds. A few days later, he won the 100m butterfly final by 0.01.
Phelps, who also won six gold medals at Athens in 2004, immediately declared his intention to keep going through to London but initially struggled for motivation.
It was only last year, when he lost his crown as the world's premier swimmer to compatriot Ryan Lochte, that he rediscovered the desire to churn through the training laps.
"I'm literally enjoying myself. It's something I haven't been able to do in a long time, over the last three years," he said.
"It's the right time to get excited again. I'll be ready. It's going to be a fun six months and I'm going to be as prepared as I can."
Phelps, 26, remains coy about how many events he will swim in London, saying he will decide the magic number on how well he performs in the lead-up to the U.S. Olympic trials in June and July, but said he was feeling confident about his chances.
"I'm in a lot better spot now than I was in any time over the last three years. Physically I'm in better shape, mentally I'm in better shape since Beijing," he told Reuters in an interview at a Boys and Girls Club in the Bronx that he helps fund through his foundation.
"I haven't been as serious and conditioned as I have now so now it's just working on all the small things that will make the big difference in the end."
Phelps already ruled out competing in the 400m individual medley, an event he won at Athens and Beijing, but said the toughest race to win in London could be the 4x100m freestyle relay after the U.S. finished third, behind Australia and France, at last year's world championships in Shanghai.
"The 4x100 relay is probably the toughest one," Phelps said. "We just want to be able to put up our fastest guys that we think have the best shot and that's all you could ask for."
(Editing by Frank Pingue)