Hot Bodies

Mark Ballas may be a dancing machine by night -- but he's also a sweaty, half-naked ass-kicking machine by day ... and TMZ has the video to prove it.

We caught the "Dancing with the Stars" pro kicking, punching, and kneeing the crap out of his trainer at True Warrior Fitness in L.A. yesterday -- and we gotta say ... it's pretty impressive.

After the session, Mark said his trainer told him, "If you can dance, you can fight."

"Underworld" star Kate Beckinsale showed off her ridiculously sexy bikini body while on vacation in Mexico with her lucky husband Len Wiseman on Tuesday.

No fists were thrown when Channing Tatum stripped off his shirt to reveal his buff, hairless chest while filming his male exotic dancer movie "Magic Mike" on a boat in Tampa on Tuesday.

Voila.

Kelly Rowland just came clean about her breasts -- revealing she got implants a few years back because she was tired of having "little nuggets for boobs."

Rowland told British Cosmopolitan she got re-racked back in October of 2007, saying, "It's something I really wanted to do for myself. Not for a man, not for work, for myself. And I love them!"

Rowland also said she didn't get the boob job on a whim, explaining, "The decision was 10 years in the making, so I'm comfortable talking about it."

No wonder she's been having trouble keeping 'em covered up.

Christina Aguilera sang "Dirty Diana" and "Smile" at the MJ Tribute concert in Wales this weekend.

It was gripping.

Let's put it this way..... someone should replace that dog Mona Lisa with Irina Shayk's most recent nude photo shoot ... it would definitely boost ticket sales at the Louvre.

The photo (ink tragically included) adorns a new coffee table book commissioned by Diddy and Interscope chairman Jimmy Iovine -- featuring lots of hot chicks from all over the planet -- to honor the female butt.

It's called "CULO" -- Spanish and Italian for ass -- and it's out next month.

64-year-old Arnold Schwarzenegger knows quality when he sees it -- and last Friday in his hometown of Thal, Austria ... the bodybuilding legend grabbed a handful of his own backside.

The statue was erected in honor of Ahnuld's legacy -- and The Terminator himself stopped by for the grand unveiling.

Lacey Schwimmer is proving those Jessica Simpson mom jeans comparisons are a huge stretch -- striking a yoga pose yesterday in West Hollywood that shows the only thing big about her ... is her flexibility.

After fighting with Kelsey Grammer in family court over visitation of their two children on Friday, "Real Housewives of Beverly Hills" star Camille Grammer escaped for some relaxing bikini time in Palm Springs with her new boyfriend and her kids this weekend.

Getting booted of "Dancing With the Stars" in week one is working out just fine for Ron Artest's partner -- because Peta Murgatroyd just signed a SIX FIGURE deal to fight cellulite.

Sources close to Murgatroyd tell TMZ she's working with Adonia Organics to endorse their cellulite serum -- which claims to reduce the dreaded "c word" in just nine minutes. And, yes ... we're told Peta's killer legs will be on full display for the campaign.

Finally, an upside to cellulite.

Everyone's favorite teenage bride, Courtney Stodden, is tired of hearing rumors she's had work done -- so she took to the beach yesterday with her 51-year-old husband, Doug Hutchison, to pose for a series of pics and prove her doubters wrong.

Suelyn Medeiros -- the Brazilian model who actually DEFEATED Bar Refaeli in a muddy bikini contest -- went to Vegas this week ... and yeah ... this happened.

Nancy Grace is adamant ... her nip did NOT slip on "Dancing with the Stars" last night ... and insists the object that poked out of her dress last night was merely a PASTY!

Grace tells TMZ ... "When I got dressed, I was wearing Petals (nipple covers) and an industrial strength bra ... my dancing dress also had a bra sewn into it."

Nancy adds, "I have been judged guilty without a trial ... I will go to my grave denying the nip slip."

From the looks of Heather Locklear's gorgeous booty in Hawaii, you'd never know she just turned 50.

Like Ashlee Simpson, Locklear showed off her amazing body in a polka dot bikini with fiance Jack Wagner this weekend.

Being a half century old never looked so damn good.

Derek Hough proved he can stomach his "Dancing with the Stars" competition by showing off his lean, ripped and hairless chest & abs this weekend.

Doing the Viennese Waltz with Ricki Lake does his body good.

While in Mexico this weekend, former singer Ashlee Simpson rocked a polka dot bikini which showed off her hottest asset.

Who knew Ashlee would turn out this good in the end?