How Swiss maestro Federer is getting better with age

17-times Grand Slam winner Roger Federer conceded he has changed some things because of his age.

Roger Federer dominated France's Richard Gasquet in a 6-3, 6-3, 6-1 scamper into the semi-finals of the US Open on Wednesday.

Federer seemed intent on beating the rain that was forecast to hit Flushing Meadows as he safely stormed into the last four, where he will face fellow Swiss Stan Wawrinka.

The fifth-seeded Wawrinka, the reigning French Open champion, advanced with an equally unstressed 6-4, 6-4, 6-0 victory over big-serving South African Kevin Anderson.

Federer and Gasquet both employ one-handed backhands, but apart from that elegant stroke there were very few similarities.

Federer, 34, could hardly miss and Gasquet all too often played the role of innocent bystander in the 87-minute mauling.

The Swiss maestro uncorked 50 winners to a mere eight from Gasquet and the record 17-times Grand Slam winner has been looking like a new, improved, revitalized model of late.

"Since a few years now, or many years, I have tried to look at the big picture to hopefully still be playing at a high level at this age," Federer said.

"I have been able to take the ball earlier, and I think I'm volleying better than I have the last 10 years."

Federer did concede he had changed some things because of his age.

"I guess I'm more professional these days. When I was coming up on tour I would bounce up and down for two minutes and then just walk out to the practice and do almost the same for the match.

"These days I take more time, put in more of the core exercises, do more stretching. Sometimes I just can't wait to get off the table again, honestly. It's nice not to be on there all the time."

The father of two sets of twins, he said sleeping is also a big part of his preparation.

"Sleeping has become quite important. I make sure I sleep enough, as well," he said.

"I believe it's really the sleep that gives you energy again down the road. That's why the next two days are very important for me in terms of sleeping."

Asked about his sleep "target", Federer showed he likes to think big.

"In terms of sleeping? Hopefully nine to 10 (hours)," he said.