While I'm generally not a fan of the style of the current "Playboy look", I have noticed a fitness tendency in centerfolds of recent years. (And I'm not just talking about
Rebekka Armstrong's road from slender centerfold to brawny bodybuilder.)
Amy Sue Cooper, Playboy's 2005 Cyber Girl of the Year, is a good example. She's got a nice gym body with great abs and overall athletic look. There's a gallery (NSFW) of Cooper at FoxHQ. Another (NSFW) gallery is here. There's also a clothed, but still not particularly safe for work, gallery here, at Beyond Hollywood.
Another recent centerfold, Alison Waite (May 2006), is actually noticeably muscular. In photos Waite's upper-body muscles - especially biceps, triceps and delts - are often apparent. While centerfolds of the 50s and 60s sometimes seemed a bit muscular, I believe it's only in recent years that Playboy has returned to featuring centerfolds with any kind of evident physical strength or athleticism. Like Cooper, Waite's field of study is medical-related: gerontology, of all things. (There's an obvious gag here about centerfolds studying to knock people out and keep the elderly vital.) Waite has NSFW galleries here and also at Bad Girls Blog.
(Note--this is defined as "at the time they were Playmates," so Rebekka Armstrong doesn't count. :D )
1--Jenny McCarthy--People forget, but she played a couple of sports in high school. Was downright stocky by Playmate standards. Hit an awesome biceps shot in one of her earlier videos. Let it all go later, unfortunately.
2--Julie Clarke--Made a point of emphasizing her workout regimen in her article. Had butt you could bounce a quarter off of.
3--Kelly Monaco--Lifeguard. Swimming. 'Nuff said.
As a long time subscriber of Playboy I believe they have gotten more athletic very gradualy over the years,With spikes here and there as mentioned above (But there where a ton more Ie Jennifer Walcott had a hardBod).
Playboy has even gone futher though with thier Hardbody Series, Though again they seem to be very careful to show them still soft;yet hard:).