ANDY Murray believes he is reaping the rewards of his strength and conditioning programme as he heads into the second week of the US Open in New York.
British number one Murray, 21, has had his best year as professional, winning three ATP Tour titles and reaching his first grand slam quarter-final at Wimbledon, all of which has seen him rise to his highest ranking to date, number six in the world.
He was facing US Open 10th seed Stanislaw Wawrinka of Switzerland in the last 16 of the final grand slam of the year having come through a gruelling five-set thriller against Jurgen Melzer of Austria on Saturday, spending almost four hours on court after going two sets to love down against the world number 48.
It was the eighth five-set victory of his career out of 12 that have gone the distance, the fifth in succession and the third time he has come back from two sets to love.
The first such victory came in 2006 in a Davis Cup tie against Andy Ram of Israel, while the second was his classic Wimbledon fourth-round encounter with France's Richard Gasquet on Centre Court earlier this summer.
Murray admitted such stamina-testing heroics had been the stuff of dreams when he first turned professional as a 17-year-old in 2005 and his fitness was repeatedly called into question.
"I think experience can help a lot," Murray said. "You know, when I played Wimbledon the first time (in 2005), I had never played four sets in my life, never mind five.
"I think it's understandable to be a bit tired then, if you're not used to doing something before.
"Then you understand that you need to work on things but, for me, I did start to work hard after that.
"You have to respect your body as well. And I was still doing a lot of growing and what have you. You can't push yourself too hard. It's not good for your body. Now I'm starting to grow up and finish growing and I can do more weights and train harder.
"It's much easier to do all that stuff now. When you're 17 and 18, I think it's tough on the body to push so hard."
Murray said developing his fitness had boosted his confidence when faced with a long haul back into a match.
"You put in the work off the court and you've got to use it on the court," he said. "The first time I did it was in the Davis Cup.
"But for me if you feel like you can run the whole match and run all day, it doesn't matter if you've done it before or not.
"Sometimes if you come back from an injury or whatever, you might not feel that comfortable with your fitness. But I worked hard and I felt like I was able to come back."
The full article contains 495 words and appears in The Scotsman newspaper.
