She has passed Billie Jean King's record of 12 Grand Slam titles and now has only Margaret Smith, Steffi Graf, Helen Wills Moody, Martina Navratilova and Chris Evert ahead of her on the all-time list of champions. For Serena Williams, however, there is another reason why she stays in the shape that has seen her win five of the last eight Grand Slam tournaments.
"It sounds ridiculous but I mostly do it because I want to look good," Williams said after winning her fourth Wimbledon title by beating Vera Zvonareva 6-3, 6-2 in Saturday's final on Centre Court. "When I'm running I'm not thinking about winning Wimbledon, I'm thinking about looking good when I'm wearing my bikini. It keeps me extremely motivated.
"I want to live a fit life and it helps keep the injuries away. Staying fit and being healthy just makes life a lot easier. I can almost fit into a sample size when I need to borrow clothes from different designers. It's just better for my lifestyle. This is the most consistently fit I've been, so that's really important."
Williams won her first Grand Slam title at the US Open in 1999 and her sixth at Wimbledon in 2003. In the next four years, as her off-court interests in fashion and acting developed in inverse proportion to her fitness, the American had just two Australian Open titles to show from the Grand Slam events.
Today, however, having rediscovered both her focus and her fitness, Williams' rule at the top of the women's game is all but unchallenged, even by her sister, Venus, who has not won a Grand Slam title for two years. The Belgian comeback queens, Justine Henin and Kim Clijsters, may provide some sort of threat in tournaments to come, but there is little sign of any other challenge to Serena's dominance.
Williams said she never gave much thought to chasing King's record and does not have her eyes set on any other milestones, such as the 18 Grand Slam titles won by both Navratilova and Evert. "I never really thought about my place in history, so to say, because then if I do that I become complacent," she said. "I don't think I would feel I had anything else to prove if I thought to myself: 'Wow, I won all those Aussie Opens and all that. That's pretty good. What? I'm still playing?' I don't want to think about all that. I just focus on the moment. I live for the day, on the tennis court."
The Williams sisters have won nine of the last 11 Wimbledons, Maria Sharapova (in 2004) and Amélie Mauresmo (in 2006) being the only two players who have denied them since the turn of the century. Serena is now only one win away from her sister's Wimbledon tally. "That would be cool to equal her," she said. "I just want to keep our name on that board, just keep our name going, that's kind of cool. Williams, Williams, Williams, Williams every year is pretty."
How long did she think the run could go on? "Who knows? Honestly, I'm really happy that a Williams won this year, but you never know what even next year brings. That's why, like I said, I try to live for the moment, because you never know what happens tomorrow. I just want to keep doing my best."
The only problem for the sisters might be knowing where to put their trophies, which are scattered around the houses they share in Florida and Los Angeles. "I have other trophies that I use for my make-up brushes and I use one to serve lemonade out of," Serena said.
Had she had the same experience as Rafael Nadal, who says that his Wimbledon trophy is the one that remains in perfect condition? "Rafa must be doing a much better job of looking after his trophies than me. I don't polish them. I keep them as and where they are. Our whole thing isn't materialistic. It's about other things – having fun and enjoying life and living with the family and being spiritual. It isn't just about winning trophies. There is just so much more to life for me."
Nevertheless, would she be treating herself to something after banking her £1m prize-money from Wimbledon? "After Australia I treated myself a lot," Williams said. "I'm just working on paying off my mortgage."
On the evidence of the last fortnight it will not be long before that loan is paid off. Williams took an average of just over one hour to beat her seven opponents, did not drop a set and never looked likely to be detained for long in the final. Zvonareva, who at No 21 in the world was the second lowest-ranked Wimbledon finalist in history (behind Venus Williams, who won the title three years ago when world No 31), will rise to No 9 in today's updated list, but there is a chasm between the likes of the 25-year-old Russian and the American sisters.
Serena plans to "relax and chill" by way of celebration, but she will soon be focused on her next challenge at the US Open. "I really come to win the Grand Slams," she said. "I personally hate to lose, whether it's at Wimbledon or at a small tournament, but for a reason I get super-focused for the Slams. It's intense and for two or three weeks you have to have ultimate discipline and really be mentally there."
Roll of honour
Men's singles champion
R Nadal (Sp) beat T Berdych (Cz Rep) 6-3, 7-5, 6-4. Prize money: £1m
Ladies' singles champion
S Williams (US) beat V Zvonareva (Rus) 6-3, 6-2. Prize money: £1m
Men's doubles champions
J Melzer (Aut) & P Petzschner (Ger) beat ......... R Lindstedt (Swe) & H Tecau (Rom) 6-1, 7-5, 7-5.
Prize money: £240,000 (per pair)
Ladies' doubles champions
V King (US) & Y Shvedova (Kaz) beat E Vesnina & V Zvonareva (Rus) 7-6, 6-2. Prize money: £240,000 (per pair)
Mixed doubles champions
L Paes (Ind) & C Black (Zim) beat W Moodie (SA) & L Raymond (US) 6-4 7-6. Prize money: £92,000 (per pair)
M Fucsovics (Hun) beat B Mitchell (Aus) 6-4, 6-4.
K Pliskova (Cz Rep) beat S Ishizu (Japan) 6-3, 4-6, 6-4.
L Broady & T Farquharson (GB) beat L Burton & G Morgan (GB) 7-6, 6-4
T Babos (Hun) & S Stephens (US) beat I Khromacheva (Rus) & E Svitolina (Ukr) 6-7, 6-2, 6-2.