Fitness & Exercise

5:17 PM PT -- A rep for the NYC Marathon tell us Kevin Hart finished the race with a time of 4 hours and 5 minutes; Karlie finished at 4 hours and 41 minutes; Tiki finished at 4 hours and 38 minutes.

With great distance comes a great responsibility to run a decent time -- which Kevin Hart, Karlie Kloss and other celebs took up in the streets of New York this weekend.

A handful of stars threw on their running shoes Sunday and took part in the annual New York City Marathon -- all 26.2 miles of it -- including Kevin, Karlie, "Catfish" host Nev Schulman and ex-Giants running back Tiki Barber ... among others.

Kevin was all smiles for the camera ... which might've even made him miss the start of the race. As you can see, he wasn't quite ready for the starting shot. Karlie, on the other hand, was kickin' ass -- hitting mile 13 in stride.

The winner of the NYC Marathon turned out to be Shalane Flanagan ... the first American woman in 40 years to win the race. She came in at just under 2 hours and 27 minutes.

Marshawn Lynch ain't one for motivational speaking ... so when he visited his old high school, he decided to throw on some pads and straight WRECK fools at team practice.

'Shawn shared a video of himself droppin' sweat with the boys at Oakland Tech -- the place where Beast Mode all began -- and he didn't hold back ... taking on swarms of tacklers and even stiff-arming one kid to hell on his way to the end zone.

No word on when the video was shot -- but we're looking into it.

Lynch won't suit up for the Raiders this week after pushing a ref last Sunday ... but it's good to see he's welcome back at Tech -- even if he's smashin' on the young fellas.

Baby, Bruce was born to puuuuuump ... up ... in the only gym he could possibly walk into with his head held high.

Yes, Bruce Springsteen was working on his fitness Monday morning by cruising into a Jersey Strong gym ... 'cause it's only right. As you'd expect from the Boss -- no yoga pants or spandex shirts. Just a white tee, flannel and jeans. He even stopped for photos with a couple fans.

Afterward Bruce was asked how the sold out one-man show on Broadway is going. It's already been extended 10 weeks to February 2018. So, yeah ... his answer says it all -- he's on fire.

There's no grey area when it come to Jennifer Lopez's best asset, which was on full display Friday in NYC ... in yoga pants.

J.Lo still had a glow to her leaving her SoHo gym, but you'd never notice it if her butt caught your eye first.

So what does J.Lo's workout include? If it ain't downward dog, we're guessing it's a ton of squats because that booty is only getting better with age.

Here's Jean-Claude Van Damme and UFC ring announcer Bruce Buffer proving 60 is really the new 30 -- lookin' absolutely JACKED at a workout sesh.

The pic comes to us courtesy of Buffer ... who says he was droppin' sweat with his old buddy JCVD at a Gold's Gym.

Pretty crazy -- Buff actually looks BIGGER than Jean-Claude ... though the movie star gets props for his ripped-up arm. Bottom line -- both are in insanely good shape.

Probably helps that JCVD's still kickin' ass in "Kickboxer" reboots ... almost 3 decades after the original!

You're looking at Maria Sharapova's worst nightmare -- a fully SNAPPED BACK Serena Williams ... looking fit, focused and ready to beat that ass ... less than a month after giving birth.

Serena gave birth to little Alexis Jr. on Sept. 1 -- and spent several days in the hospital due to "complications."

But early Thursday morning, Serena posted her first full-body post-preggo selfie -- and she looks superhero fit.

Seriously, this is a woman who won a major tennis tourney while pregnant -- who crushed it in the gym at 35 weeks pregnant -- and whose mother guaranteed she'd return to dominate the pro game after the kid was born.

So, when will Serena return? The next Grand Slam is the Australian Open in January ... the same tourney she won while she was in her 1st trimester.

You've been warned.

Chuck Liddell says he hasn't ruled out an MMA comeback -- and if he does return, Chael Sonnen would be a great "warm-up fight."

The 47-year-old UFC legend has been training pretty regularly at Jay Glazer's Unbreakable Gym in L.A. -- and we're told he's still in damn good shape.

And with all the comeback rumors out there, we asked Chuck straight-up what the deal is.

"Chael's an easy fight," Liddell says ... "If I was gonna come back, it's a good one. It's a good warm-up fight. He's got a big mouth but not much behind it."

Whatever Anthony Bourdain's eating these days ... it does his body good.

The celebrity chef and 'Parts Unknown' host showed off his 6-pack and tats at the Hilton hotel pool in Rome. His inked up gf, Italian actress Asia Argento, ain't no slouch in the abs department either.

They started dating earlier this year, and they've been doing crunches ever since. Kidding. Maybe.

Jared Leto lost 35 lbs. for "Dallas Buyers Club" and morphed into the gangly Joker for "Suicide Squad," but when he's just playing Jared the rocker in his band, 30 Seconds To Mars ... he's ripped!!!

Jared shared this pic of his hot bod on Instagram and asked folks to caption it. He also added the hashtag #walkonwater. It's the name of 30 Seconds' new single ... so, pretty genius marketing.

He's missing a few packs to a 6, but we'll let it slide on behalf of those bulging pectorals and the whole putting-the-rock-in-rock-star thing.

Francia Raisa is getting ripped again ... but this time we're talkin' muscles.

Selena Gomez's best friend is back in the gym getting her sweat on just months after donating her kidney to save Selena's life. You can see her scars where doctors made the incision, but we suggest you check out her it's-always-bikini-season bod.

The surgery took its toll on Francia, a fitness queen forced to put her workouts on hold.

She wasn't ready to pose for paps last week on the set of her new TV show, "Grown-Ish," but she's now ready to show us what she's got.

And we dig it.

Lonzo Ball is gonna give it all to you in this video ... get ready.

You know dude's got hops ... so maybe the INSANE dunk is ho-hum everyday action for you (crazy). But check out the dance he busts after freakin' the dunk at the Lakers practice facility and ask yourself ...

Should Odell Beckham Jr. be looking over his shoulder? Is there a new king of the dance ready to take over professional sports and captivate us with his pre-game and in-game gyrations?

UFC superstar Luke Rockhold kicked so much ass this weekend, his foot exploded.

Well, it certainly blew the hell up.

Take a look at video of Luke's insanely swollen and bruised right foot -- which he earned during Saturday night's dominant TKO victory over David Branch at 'UFC Fight Night' in Pittsburgh.

Maybe put some ice on it?

The good news ... Rockhold seems pretty comfortable recovering while chillin' at a rooftop pool in the Steel City.

Could be worse ... could be David Branch's face.

Don't call it a comeback -- cause it's a looongshot -- but Stephon Marbury says he's gunnin' for an NBA return!

The 40-year-old announced the news on social media, adding that -- "I still have a lot of go in me as a player and at 40 being able to play at a high level is a gift."

Remember ... Starbury left the league 8 YEARS ago after a string of sketchy off-court incidents -- highlighted by him eating Vaseline straight out of a jar.

He famously packed his bags for China ... and became the most legendary player in Chinese Basketball Association history (for real, dude's already got his own statue).

Now, Marbury says he's ready to "turn towards the last page of my basketball diary that I've been writing since 95 when I left Lincoln High."

Will a team take a chance on him? We'll see ...

Demi Lovato is becoming a much more dangerous person -- she just earned her blue belt in Brazilian Jiu-Jitsu ... after training her ass off for the past year.

The blue belt is one level above white belt -- and 3 levels away from being a black belt.

The singer was awarded her new rank Monday at Jay Glazer's Unbreakable Gym in L.A. -- where she's spent the past 12 months grappling with MMA superstars like Chuck Liddell and Randy Couture.

Glazer -- who owns the gym -- flew back to town specifically to present Lovato with the new belt and tweeted, "I'm more proud of the work [Demi] puts in with nobody watching than i am what she does with the world watching."

"Congrats on achieving your blue belt today in #bjj, YOU put the grind in!"

Most blue belts usually train for about 2 years before moving up to the next level, purple belt.

It's been a helluva past few days for Demi -- from belting out the national anthem for the Mayweather/McGregor fight to performing for the VMAs ... and now this.

With great power ...

PETA has a friend in Bob Harper, who says he's cut meat completely out of his diet after almost dropping dead from a massive heart attack back in February.

We got the 'Biggest Loser' trainer and host in Bev Hills Tuesday and he looked healthy as a horse.

If you thought Meek Mill and Drake had NOTHING in common, TMZ Sports has hilarious video to prove you totally wrong ... Meek airballin' 3's just like his former hip-hop rival!

You might remember ... Drake drew nothing but air warming up with the Kentucky Wildcats a few years ago, and has been roasted on the 'net about it since.

Meek got his chance to one-up his rival at James Harden's JH-Town charity game this past weekend, but the Philly spitter came up waaay short -- bricking a trifecta of 3's during warm-ups.

In all fairness to Meek, this was for a good cause ... but still, work on that form, bro.