Roger Federer says with more players staying on the circuit longer, he and No. 1 Rafa Nadal can redefine their careers.

The former No. 1 is 36, while Nadal is 31. This season, they have split the majors between them, and seem pretty healthy. According to Federer, there are a lot of reasons older players can keep playing these days.

“A lot of guys were retiring between 29 and 32, so now it feels like most guys, you are going to retire probably between 31 and 35, it seems like. But then again, every player needs to decide for themselves what the body can take, where your life's at, do you have family, how much is the traveling bothering you,” Federer told press at Shanghai.

“Prize money is only going up, so maybe that's another incentive to also keep playing. Players also staying healthy, healthier in the process, because we invest probably more into traveling with massage therapists and physios, do more rehabs. The tour provides us with better services, at the tournaments. Traveling is easier today than maybe it was still 30 years ago. We can fly more direct today.

"And all these things make it that we can play longer. And then if the best players in the world can lead the way, like Rafa, myself have, and [Andre] Agassi and others, I think that inspires the next generation to maybe try to do the same, at least.”

Federer also talked about the potential of men's tennis in China and other parts of Asia, where the sport has really grown, with an increase in the amount of tournaments and top-level female players.

“It seems like at the moment the Chinese are definitely having more players than ever, after 100 down to, I'm not sure, 500, 1000,” Federer said. “I think there is a broader spectrum of players playing in that region now, which is already a beginning. It seems like the US Open junior champ is probably going to make a run into the Top 100 for the first time [for a Chinese male] or maybe Top 50, and for that matter, from what I'm hearing, what his potential has got. And that would be a massive thing, inspiration for a lot of the young guys after that.

"Same with Kei Nishikori breaking all records for a Japanese player. That's great. I think we do see more Asian players. Of course we don't have [the former player] Paradorn Srichaphan anymore from Thailand, but in the future we'll see more Asian players coming through. I just think tennis, as it's not just an endurance sport where you can just go sort of after textbook 'this is what you have to do to get to the top,' it's more of a game. So I think you just need a lot of numbers, and then you need the passion and the right coaching.

"Nevertheless, I think having big tournaments like Shanghai Rolex Masters here is hopefully going to strengthen the future of Asian tennis. I have been a big believer in this continent.”