Bear Grylls has been running wild with celebrities for an incredible eight seasons — and there's never a dull moment when it comes to their time in the wilderness.
The celebrated British adventurer, 49, has taken a plethora of stars out of their comfort zones and pushed them to their limits for a show which seemingly knows no bounds.
But beyond the 'mouthwatering' meals of creepy crawlies and adrenaline-fueled tasks, what are Bear's famous guests really like?
From former POTUS Barack Obama to Magic Mike's Channing Tatum, Bradley Cooper to Oscar winner Brie Larson, National Geographic's Running Wild has seen Bear set up camp with the best of them and now he's talking exclusively to HELLO! to take us behind the scenes of the hit show.
Running Wild's most impressive guest
When asked which of the A-listers impressed him the most, Bear made a revelation.
"The women are often the surprise heroes of the show," he confessed. "Because we can all at times be guilty of judging books by their covers. Just because someone's petite, it doesn't mean that they're not going to be strong. Also, just because somebody has never done something like this, doesn't mean they're not totally capable of it."
© Getty ImagesFrom the multitude of female guests including Kate Hudson, Julia Roberts, Tamron Hall and Kate Winslet, Bear honed in on one tough star in particular.
"Natalie Portman. She's got it all," he remarked. "You know, she was really good fun, she was relentless and so determined. Not only that but she was positive, kind, and really easy to hang out with."
This is particularly impressive, given that in that episode Natalie drank water filtered through Bear's underpants and dined on prickly pear while watching her host consume maggots.
Bear on 'humble' Bradley Cooper
Bradley Cooper's Running Wild episode in the Wyoming Basin was an emotional one, during which he reflected on his 19-year sobriety after zip-lining across a 100-foot ravine.
© National Geographic for Disney/Jeff EllingsonBut the challenging conversation was likely made slightly easier given their friendship.
Bear spoke fondly of the Oscar-nominated Hollywood actor, 48, when he said: "He's beyond the fame even though he is one of the biggest stars in the world. He is just one of those super humble guys."
In fact, he once came to visit Bear in the UK with his daughter, Lea - who he shares with is model ex Irina Shayk. "Bradley is such a lovely dad. If I ask him what food I can get in for Lea, he's so laid back. He'll just say 'whatever you have in'. He's just a sweet guy."
© Getty ImagesHow Bear Grylls was left shocked by Barack Obama
When it was announced that Barack Obama, 62, was going to appear on Running Wild, many were convinced it was a joke.
The leader was President of the United States at the time of filming, and a reality TV show seemed an unlikely career venture. "This was fairly early on in Running Wild," Bear recalls. "It certainly helped the show. But it was pretty unique.
© Getty Images"No sitting President had done any show like this. I remember when they announced it, I was in America and I remember seeing a news clip and it came up at the bottom of CNN; 'Obama announces he's going on Running Wild with Bear Grylls'. The news anchor was like, 'oh, gosh, hold on. This must be for when he finishes next year as President.
"But it wasn’t, and Obama was the first sitting President ever to do a reality TV show. Wild."
Rita Ora vs. Florence Pugh
There's nothing wrong with a little competition between friends, and that's what Bear got when it came to Rita Ora and her good friend Florence Pugh.
The Don't Worry Darling actress, 27, had no trouble getting down and dirty for a few days in the wild and wowed Bear with her 'far from Hollywood' attitude to just about everything thrown at her.
© Getty Images"She was brilliant," he told HELLO! about Florence. "She was no drama, and absolutely nothing phased her."
Her pal Rita, 32 - who also took part in Running Wild - once asked Bear just how well did Florence do. "After the show with Florence, I bumped into Rita on a flight to Los Angeles," said Bear. "Rita jokingly asked how she compared to Flo. I said, 'you're both incredible!' And that was the truth, they genuinely were."
Are Bear Grylls and Channing Tatum friends?
It appears that Magic Mike's Channing Tatum, 42, is a glutton for punishment because he's taken part in Running Wild several times. Bear confessed to HELLO!: "It’s a privilege to call him a friend". Chan loves adventure, and he knows I'm not going to get him killed," he added with a laugh.
"It’s really fun always to go away with him. It’s like an an adventure with a good buddy. He knows the crew and loves the experience. I think he considers it like an exciting holiday for him, that he doesn't have to plan."
© Getty ImagesIs there anyone Bear hasn't got along with on Running Wild?
Hunkering down in the wild for a few days with a stranger isn't easy, and yet Bear appears to put everyone at ease - even while navigating swamps, snakes and sleepless nights. But is there anyone who Bear simply couldn't get along with?
"Not really to be honest," Bear said without hesitation. "It's like a guiding job with amazing people. It's not for weeks on end. It's just a few days and the people who come on the show invariably want to be there.
© Getty Images"That's not to say it is easy. They definitely go through the mill a bit, cold, wet, hungry, that sort of thing. But they're willing to trust me with their life, their brand, their experience and I feel incredibly grateful to be in a position where they do that."
Get sneak peeks and free episodes all on Nat Geo TV.
Get the lowdown on the biggest, hottest celebrity news, features and profiles coming out of the U.S. Sign up to our HELLO! Hollywood newsletterand get them delivered straight to your inbox.
