DELRAY BEACH, Fla. -- In most careers, when you've turned 30, you're finally coming into your own and starting to receive some respect.
Not so with sports. As tennis stars start approaching this milestone age, they begin to hear the dreaded questions: When will you retire? How much longer do you want to play?
Today, however, there's a group of 30-and-over players who are not only still in the game but more than holding their own. Proof? Two months have not even gone by on the calendar and three ATP World Tour singles titles have been captured by players who are into their 30s. Moreover, in this week's ranking, more than a fifth of the top 100 players -- 23 to be exact -- are at least three decades old.
"Age is just a number on your passport," said Jurgen Melzer, who became a winning 30-year-old when he captured last week's Memphis title.
Chief among the 30-something crowd is Roger Federer, who is 30 years, 6 months old. Federer ranks No. 3, and he's finished in the top three the past nine years (five of those years at No. 1). He already won his first title of 2012 at Rotterdam two weeks ago, which guarantees continuation of his winning at least one title every year -- a span that has now reached 12 straight seasons.
Although Federer is the kingpin of the tour's senior citizens, he has some admirable company.
At this week's Delray Beach International Tennis Championships, seven of the 32 main-draw competitors come in at over 30. Two of those players -- No. 19 Melzer of Austria, who at 30 years, 9 months old is the oldest guy ranked in the top 20, and No. 45 Jarkko Nieminen of Finland, 30 years, 7 months old -- are the other two 2012 tournament champions.
Melzer entered the Memphis tournament ranked No. 38 and overcame a broken toe, which he injured at in his hotel last week. "That's why to turn on the lights," he said. Melzer bypassed top seed John Isner in the quarterfinals, 33-year-old Radek Stepanek in the semifinals and the red-hot Milos Raonic 7-5, 7-6 (4) in the finals.
Raonic came into the final having had his serve broken only twice in his previous eight matches. He was broken only once en route to defending his San Jose title and once until the final in Memphis. Melzer broke him twice in the Memphis final.
Melzer's success helps to ease the distress of having missed most of last year with a bad back. But he seems to have done the work to get back to top playing condition.
"The older you get, you have to listen to what your body is telling you," Melzer said. "Of course, you have to make adjustments all the time."
Nieminen won the Sydney title in January, which was his second career title and first since winning the 2006 Auckland trophy. He believes his class of players are too good to discount just because they're no longer in their 20s.
"I think the year I was born -- I was born in '81 -- it was very tough competitions in the juniors," Nieminen said. "It was one of the best age groups, '81, '82, and now we're 30 and there's so many good players that can still compete at the top level. Many of us are still able to win ATP tournaments. And obviously one of them is Federer, who is still playing great."
The other five over-30 players in the singles main draw at Delray Beach are: No. 41 Ivo Karlovic, who turns 33 Tuesday; No. 48 Olivier Rochus (31); No. 66 Xavier Malisse (31); and No. 165 Tommy Haas (33) and No. 186 qualifier Michael Yani (31).
Malisse, the onetime boyfriend of Jennifer Capriati, has won two of his three career titles at Delray Beach and also was a semifinalist at Wimbledon. Although he's 1-5 in singles this year, he teamed with 40-year-old doubles specialist Mark Knowles to win the San Jose doubles title. Knowles is the oldest player to win an ATP doubles title since John McEnroe won the 2006 San Jose title with Jonas Bjorkman at age 47.
Malisse has altered his training to be more about off-court strength and endurance than hitting on court, which he feels is imperative for an older player.
"It hurts a little bit more in the morning, but nothing major," said Malisse, when asked how the wear and tear of his 13 previous years on tour have affected him. "I think a lot of people over 30 are playing longer and better. I can't really complain because I feel fine, actually. The game's just changed a lot, and it takes a lot longer to get to there to a good level."
None of the 30-something guys appear surprised to find they're still making noise on the tour. In fact, they believe it's the wave of the future.
"I think that's one of the keys is you really have to practice smart, rest enough, plan your tournament calendar really smart and then also you need to have some good luck," Nieminen said. "If that happens, then you are able to play pretty long. I'm hoping I can still play a few more seasons."
He's not alone in that that sentiment.
"People are going to play longer and longer," Melzer said. "They're going to play until they're 35, so why not be peaking at 30?"
Sandra Harwitt is a freelance tennis writer for ESPN.com.