Fitness & Exercise

It's better than any Doublemint commercial we've ever seen -- WWE's incredibly hot Bella Twins getting a stretch in Monday on an L.A. beach ... all while wearing teeny tiny bikinis.

Chew on that.

New parents Wiz Khalifa and Amber Rose have figured out how to divide their parenting chores -- he pushes, she carries.

The superstar couple -- who married this past summer -- went for a stroll yesterday in West Hollywood with their son, Sebastian, who turns 1 next month. Wiz pushed the empty stroller ... while Amber did the heavy lifting.

Amber says it took her almost a year ... but she got back to her pre-baby shape ... by working out every day.

Lookin' good.

Amanda Bynes' road to recovery includes one big cosmetic change ... removing an angelic tattoo from her body.

Amanda's been working out a ton lately -- hitting the gym and doing some power walking -- and she's also slowly erasing a pair of angel wings from her right forearm.

The tattoo -- which was prominent during her blue wig days -- is faded in recent shots of Amanda walking around her parents' neighborhood in Thousand Oaks, CA ... where she's been living since getting out of a rehab facility last month.

Your mom's Zumba class just got HARDCORE ... 'cause TMZ Sports has learned, UFC face-smasher Mark Munoz is taking up dancercise -- and we dare you to crack a joke (at least to his face).

Munoz -- who's currently ranked #7 in UFC middleweights -- hit up the LA Fit Expo on Saturday ... where he fulfilled his New Year's Resolution of (that's right) learning Zumba.

And guess what -- Mark says he loved the class so much ... he's actually considering using some of the moves in his regular MMA workout routine.

TWO MILLION butt aficionados can't be wrong ... which is why fitness model person Jen Selter has become the Internet's reigning QUEEN OF ASS!

And she'll have no trouble holding the title -- if she avoids dairy and spicy foods.

Drizzy Drake’s been on a fitness RAMPAGE … posing for shirtless pics in a Bieber-esque frenzy ever since he started dropping lbs for his new tour … and it looks like all the work is paying off.

Drake's trainer posted this latest installment on Instagram today … and he looks jacked with a noticeable four pack … and wearing an expression that says “even I’m surprised I look this good.”

No word on what inspired the new work out regimen ... but he's definitely starting to look more like Rihanna's type.

Never wanting to miss Upper Body Day, 65-pound Justin Bieber attempted a pull-up in Brazil on Tuesday -- and nearly burst every capillary in his face.

Kate Middleton allegedly had a baby 3 months ago -- but there is zero proof of that in these pics of the Duchess of Cambridge flashing her royal midriff all over a volleyball court.

Prince William's wife showed up for a public appearance in London yesterday, sporting wedge heels, and a banging bod that made everyone forget she was ever pregnant.

Kate gave birth on July 22 to Prince George ... and obviously hit the gym on July 23.

Women ... begin hating. Guys ... continue wishing you were Prince William.

Hines Ward proved he's an athletic beast in Hawaii this weekend -- taking part in one of the most difficult triathlon courses ever ... for 13 hours!!

The whole race went down in Kona for the Ironman Triathlon where Ward finished 1,680th place yesterday.

To complete the course ... Hines had to swim, ride his bike and run for insane lengths -- 2.4 miles, 112 miles and 26.2 miles, respectively.

After the race the 37-year old athlete said he couldn't have done it without his trainer and the man upstairs adding, "God is good! Trust me, I kept talking to The Lord to help me get through the marathon."

Lindsay Lohan and her mom Dina grabbed their running shoes ... their track suits ... and a couple of bottles of Coca-cola as they hit the streets of New York today.

Yeah, Coke isn't the drink of choice when you're working out, but it beats vodka.

Lilo and DiLo rented bikes and cruised the West Side Highway in NYC ... then ditched the bikes and worked up a sweat during a quick run -- sodas in hand -- before hopping into a waiting SUV.

Feel the burn.

Kim Kardashian is determined to move all of her baby weight back into her ass cheeks ... and by the looks of things, she's doing one helluva job.

KK hit the streets in Paris this week ... en route to a workout session at a local gym.

So, we gotta ask ...

BTW ... Kim's discovered one of the side effects of breast-feeding -- engorged boobs. Check out the video below ...

Model Vida Guerra -- famous for her backside -- had emergency surgery on her other money-maker yesterday -- replacing a breast implant that was creating a serious health crisis ... TMZ has learned.

Vida posted a pic of her exposed chest Tuesday morning ... showing her right breast covered by a large gauze pad. The problem was scar tissue forming around a gel implant.

Vida tells us back in 2011 she replaced saline implants with fancy new gel ones -- 450cc (or a full C cup). When she recently started having back pain and trouble breathing ... docs told her scar tissue had formed and had to be removed, along with the implant itself.

Vida got a new left implant during her 24 hour hospital stay -- but she's home now, doing something she never gets to do ... PIG OUT!!!

The fitness fanatic confesses she's been eating "everything in sight" ... especially pizza. Docs have cleared her to start working out again in a month.

Boob job lesson of the day: Vida says, "If I could do it over again, I wouldn't have. It's just more problems in the end."

And the front.

More smack talk in the war between two former "Biggest Loser" co-stars -- this time Jillian Michaels is firing back at Cara Castronuova with some good ol' fashioned venom-laced sarcasm.

We broke the story ... Cara -- who was a trainer on the show -- ripped Jillian apart over Michaels' poor showing at the Malibu triathlon earlier this month, calling her an embarrassment.

This weekend, Michaels returned to Malibu -- where she offered up some brand new excuses for her abysmal showing (bad wet suit, bike problems, a horse?) and vowed to do better in the race next year.

Then, it was open season on Cara.

She's 71 years old ... but that didn't stop legendary designer Betsey Johnson from doing a FULL SPLIT on stage Wednesday at Fashion Week ... while wearing a hilarious pair of pink briefs.

Who knows, maybe she's got an extremely high threshold for pain ... she is holding what appears to be a prescription pill bottle after all.

Jillian Michaels didn't just SUCK ASS at the Malibu Triathlon -- she was an EMBARRASSMENT -- so says her former "Biggest Loser" co-star Cara Castronuova.

As we previously reported, Michaels was a disaster at last weekend's big race -- admitting to TMZ she got beat by a bunch of people a world class fitness professional shouldn't have lost to ... including an 80-year-old.

But when we ran into Cara last night in L.A., the former B.L. trainer didn't pull punches -- telling us. "I would probably kill myself if that happened to me."

Cara said Michaels likely bombed because she didn't take the event seriously -- "That's what happens a lot with people that think they're in really good shape. They take things lightly and then they embarrass themselves."