David Walliams thinks Davina McCall is "strong" for competing in a Sport Relief triathlon.
The 42-year-old comic has praised the former 'Big Brother' host for taking part in the gruelling seven-day charity challenge - which sees her cycling, running and swimming from Edinburgh, Scotland, to London - and believes she is doing a great job.
David raised over £1 million for Sport Relief in 2006 by swimming the English Channel and understands the hardship Davina, 46, is going through.
Speaking to BANG Showbiz, he said: "I think it shows that in these challenges you are pushed to the absolute limit. But I know she's quite a strong person both mentally and physically.
"The best way we can get behind her is donating, because that'll be the biggest thing that will make her happiest, to know people are behind her and care."
The 'Britain's Got Talent' judge admits he couldn't tackle a triathlon like 'Got to Dance' host Davina because he is not good at running or cycling.
He added: "The reason I couldn't do a triathlon is because you have to do three different things. I'm only good for swimming, whereas on a bike, I'm too heavy, and going for a run, I'm too heavy. You have to be lean to do the other things."
In support of Davina, BT has declared today (13.02.14) Dial for Davina Day and will donate 1p to Sport Relief for every phone call made from a BT home phone line, BT business line and every call made from a BT payphone.
To participate in Dial for Davina Day, people should simply pick up their BT phone and make a call on Thursday, February 13.

Queens of the Stone Age frontman Josh Homme ripped into LA band Imagine Dragons during a foul-mouthed rant.
The band, who missed out on a gong for Best Rock Performance to the group at the Grammy Awards last month, also slammed the awards ceremony at a gig at the Bayou Music Center in Houston, Texas at the weekend.
Video footage has emerged of Josh introducing their track 'I Appear Missing' and joking: "This next song is Imagine Dragons", before being heckled by the crowd, to which he responds: "Just f***ing kidding. Wait, wait, wait, you've got to admit, you're all imagining dragons right now."
He then said: "You know, f**k everything, f**k the man, f**k Imagine Dragons and f**k the Grammys, f**k all this shit.
"We're supposed to be here with you, we ain't supposed to be, like with some, like the band's d**k in our hands."
Josh then thought about the comment and added: "Although, there ain't nothing wrong with it."
The singer and his band mates - Troy Van Leeuwen, Michael Shuman, Dean Fertita and Jon Theodore - also performed at the Grammys but had their set cut short during the show's finale, which also featured Nine Inch Nails, Dave Grohl and Fleetwood Mac's Lindsey Buckingham.
Los Angeles band Imagine Dragons, who released their album 'Night Visions' in 2012, won Best Rock Performance with their single 'Radioactive', beating Queens of the Stone Age, who were nominated for their track 'My God Is The Sun'.
Earlier this week, footage of Josh pushing an invader off the stage and calling him a "f***ing d*****bag" also surfaced online.
After pushing the man back into the crowd, he said: "Don't do that ... I don't know what you're trying to do. You're lucky I didn't f**k you up, bro. I'm here to play for you, not j**k you off, you f***ng d*****bag."

Justin Bieber's mother is 'genuinely concerned' for her son.
Pattie Mallette is standing by the 'Baby' hitmaker after his recent bad behaviour - including being arrested for driving under the influence (DUI), driving with a suspended license and resisting arrest, and allegedly being abusive to flight staff who asked him to stop smoking marijuana - but is finding it difficult to cope in the public eye.
A source close to Pattie told E! News: "As any mom of an adult child, Pattie is holding him close and talking to him about everything, but she can't make his decisions for him.
"As any caring mother would be, Pattie is genuinely concerned for Justin, and she has said in many interviews before that she doesn't have her head in the clouds and keeps in very close touch.
"She talks with him almost every day, which is likely more than any mom and a 19-year-old son ... and she is in the public eye dealing with all of this."
The source insists Justin isn't the only one going through a tough time and says Pattie has found it hard being accused of letting her son get away with his recent antics.
They said: "It's so hard to see people's opinions and accusations when they don't know her.
"If she is with Justin, she is accused of endorsing or enabling him, yet if they find out she is not with him, they accuse her for not being with her own child in a time like this."
The insider said Pattie would "never do anything to bring harm to Justin" and claims the pair have a great relationship but they have had "serious discussions" following his arrest and she never makes excuses for her famous son.
The source added: "Those close to her know from Pattie, that it's always challenging as a parent to raise your child in the way you know to be right, letting them grow as they need when they become adults and have strangers share their opinion in unfounded, often hateful ways.
"It would be hard to imagine that any parent wouldn't feel the same love, concern and responsibility as Pattie does in regard to her son's well-being. Pattie and [his dad] Jeremy both know that they are responsible before God and are focusing on their son's well-being in private."

Nigella Lawson's ex-husband Charles Saatchi has taken his new girlfriend Trinny Woodall on a romantic Spanish break.
The millionaire art dealer and his lover have been celebrating her 50th birthday by visiting art museums and dining in lavish restaurants in the country.
TV star Trinny posted a photograph of her and Nigella's ex on her Instagram account having breakfast in Madrid, along with the caption: "Half a century".
In another snap, Trinny is seen wearing a new black and white top and posts the message: "Gorgeous present", while also sharing photographs of a visit to a gallery and a snap of her daughter Lyla, 10, her child with ex-husband Johnnie Elichaoff.
Trinny started dating Charles, 70, after he split from TV chef Nigella last year. They married in 2003 but divorced seven weeks after photos emerged of him with his hand around her neck.
The break-down of their marriage was played out in public during the trial of their former aides Elisabetta and Francesca Grillo, who were acquitted of fraud in 2013.
Meanwhile, Trinny and Nigella were involved in a war of words online this week, after the fashion expert wrote a blog marking her birthday, seemingly making reference to when Charles put his hand around his ex-wife's neck in a London restaurant.
Trinny wrote: "It's great that, at 50, life can still grab you by the throat and shake you up.
"And it's even better when you've learned to cope with whatever's thrown at you - so long as it isn't a bedside lamp."
Nigella appeared to respond to the blog post by writing on Twitter: "Slut's Spaghetti -- aka pasta alla puttanesca -- is #recipeoftheday. Do I need to say anything more? (sic)"
The brunette beauty attached a photograph of the recipe, before later adding: "No agenda behind #recipeoftheday! Slut's Spaghetti an old fave of mine. (sic)"

Bella Thorne insists her upcoming album will fit everyone's taste.
The 'Winter's Tale' actress has revealed her new single will be released in the next "few months" and her debut studio collection will follow shortly with tracks from a variation of genres.
She said: "Everything is very different so it is hard to say I have some Coachella music, I have some R&B, some more Ke$ha talk-y music.
"I wanted there to be a song for everyone I don't want it to just be you hear a song on the radio and say, 'Oh that kinda sounds like Bella Thorne,' like she would sing a song like that. I want it to be so versatile and different."
The 16-year-old star has several movie roles lined up for 2014 - including 'Blended' - but she insists every bit of spare time she gets, she spends in the studio.
Although, she most looking forward to performing her songs in front of an audience.
She explained to MTV: "I don't think people realise how much work it takes to make an album. I'm in the studio for hours in that tiny little box and really the performing part is what I'm most excited about."

Christina Hendricks says it has been "a dream come true" working on 'Tinker Bell and the Pirate Fairy'.
The 38-year-old actress does the voice over for pirate fairy, Zarina, in the animated adventure and had a great time working with Disney, especially since her alter-ego is a new character which she could make her own, starring alongside other fairies including Tinker Bell.
She gushed: "It is so exciting to get a phone call saying you're going to be working on a Disney film. And then, to find out it's a Tinker Bell movie is every girl's dream. I also love the fact that the movie is about the introduction of a new fairy that we get to create from scratch. Its been a dream come true. Its been really, really fun.
"It's an honour to be part of the Disney legacy. As an actor, you always hope that you're leaving a mark or that something has been learned from watching your movie."
Hendricks admits Zarina looks "a lot" like her and is fascinated by how the animators managed to capture her in her character.
She added: "When you finally watch the finished movie, there's little Zarina doing exactly what you did in that room [studio].
"She looks a lot like me and it's really fun to think that someone could capture that through animation. It's unbelievable how lifelike it is and how realistic it is to me."
'Tinker Bell and the Pirate Fairy' will be released on February 14.

Lea Michele has been struck with grief "every day" since the death of her late boyfriend Cory Monteith.
The 'Glee' star has been left distraught since her lover and co-star died of a drug overdose last July, but she admits she's trying to get on with her life by throwing herself back into work and rising above the pain.
She told We Love Pop magazine: "You can choose to rise, which is what I'm going to try and do, but you have to be very strong. I think I'm doing the best for myself, by showing that you don't have to lose yourself, maybe someone else will feel some strength or comfort. I'm trying to do my best for him."
She added: "Going to work is no harder than being at home and being in the house and opening up a closet and seeing a pair of shows. There's this grief with you every day whatever you're doing - so I'd rather be at work with the people who I love that going through it. They're my family."
The 27-year-old actress stayed with her friend Kate Hudson for a few weeks after the death of Cory because she couldn't face the flock of reporters standing outside her house, and she insists she'll never be able to thank her pal enough for her support during such a heartbreaking time.
She explained: "I called her [Kate] and said, 'I don't know where I'm going to go because my house is swarmed [with reporters]'. She was like, 'Oh, you're going to stay at my house. ' Like it was nothing. She let my family and friends stay there. She made sure that the fridge was stocked up with my favourite juices. I'll never be able to thank her enough for what she did for me."

Taylor Swift wants her friends to always be "brutally honest" with her.
The 'I Knew You Were Trouble' singer has revealed she only surrounds herself with genuine people like Selena Gomez and Emma Stone because she wants to stay grounded.
She said: "I don't want people around me telling me what they think I'd like to hear. I love being surrounded by friends who are brutally honest and genuine.
"[We talk about] everything, except our work! It's always about reconnecting with each other, talking about relationships, love and guys - all the basic things!"
The 23-year-old country star's last album 'Red' featured deeply personal songs about her famous exes, who include Jake Gyllenhaal and Taylor Lautner, and she says her next offering will explore a similar musical style.
Taylor said: "My song writing will always have a confessional aspect, because I naturally draw on my life and my stories. I don't want to keep repeating the same things, though - you want to be able to explore those themes in different ways and have something new to say."
The blonde beauty says she doesn't actively set out to be a role model for her young fans, but is proud to inspire other girls through her music.
She told LOOK magazine: "I don't have any of that in my head when I write them. It's maybe a natural extension of me talking about not taking crap from people that others might take inspiration from. That would make me very happy if my songs can reach out to people and lead them to do something positive."

Colin Farrell was disappointed by his children's reactions to his movie 'Epic.'
The 37-year-old actor decided to lend his voice to the animated film last year so his sons, James, 10, and Henry, four, could finally watch one of his movies, but admits they weren't huge fans.
Asked if they had seen any of his work, the Irish star told PEOPLE.com at the premiere of his new film, 'Winter's Tale,' in New York City on Tuesday (11.02.14): "Epic - [but] they didn't know it was me, so that was kind of a bummer. They seemed to think it was all right. I don't think it went to the top of their favourite list of cartoons, which is a bit disappointing."
But Colin is very proud of Henry and James, who has Angelman Syndrome, a rare genetic disorder that can impair speech, movement and balance.
He said: "[James] is an absolute stud. Every day, just breaking down boundaries. He's an amazing boy."
The actor previously credited his eldest son for inspiring him to check into rehab for drug and alcohol abuse in 2005.
He said: "Everything he's achieved in his life has come through the presence and the kind of will that is hard work. He's a lot to be inspired by."

Bruce Jenner is "a bit lonely" since ending his marriage to Kris Jenner.
The 64-year-old Olympic gold medallist, who announced his split from his wife of 22 years in October, is trying to embrace his freedom and reportedly underwent a laryngeal shave to reduce the size of his Adam's apple last month, and grew his hair long, in a desperate bid to stay youthful.
A source told PEOPLE.com: "He totally has this 'I may be an old man, but I'm cool and young too' syndrome and no one can tell him otherwise.
"He's a bit lonely, but he's doing his thing. Everything in the end of his marriage just became too much for him and his freedom is really liberating. He wanted to grow his hair long, so he did it. He wants to get manicures, so he gets them."
The insider said that the 'Keeping Up with the Kardashians' star, who moved into a bachelor pad in Malibu, California when his marriage to Kris began to crumble last year, doesn't care what anyone thinks about his new image, including his youngest daughters, Kendall, 18, and Kylie.
The source said: "People in the family have brought up his hair or his clothes, whatever it is and how absurd they think it is, but Bruce doesn't care, nor does he want to listen to any kind of criticism. He thinks he looks great and cool and that's that. But at the end of the day, however ridiculous people may think he looks, he's happy about it - or at least trying to find what he's happy with - so you really can't blame the guy for that.
"He's doing what he wants to do. It's just a matter of choice and not everybody has the same taste."

Mila Kunis threw Ashton Kutcher a surprise party for his 36th birthday.
The 30-year-old actress rented out one of the 'Two and a Half Men' star's favourite restaurants, La Poubelle, in Hollywood and invited lots of his friends to celebrate the occasion on Saturday night (08.02.14).
A source told Us Weekly magazine: "It was very small. Ashton has been going there for year and years. It's one of his favourite spots, like home, so it was comfortable and they were well taken care of.
"They had been planning it for awhile. Ashton didn't want a huge thing but they got a good group together. He's certainly changed from how he used to like to party years ago. This was more of a wholesome situation. They had a great time."
The couple "looked romantic together" at the bash, as they dined on lobster, steak and quail at the French bistro.
The insider added: "Mila gets along great with all of his friends. She's like part of the crew."
A friend previously revealed that the couple, who first met on 'That 70s Show' when Mila was 14 and have been dating for two years, are likely to get engaged in the near future, saying: "They talk about getting married and having kids. An engagement is imminent."

Dave Grohl and Jordyn Blum are expecting their third child.
The Foo Fighters star's 37-year-old wife, whom he married in 2003, is set to give birth to another baby girl this year.
A source told UsMagazine.com that the couple, who already have daughters Violet Maye, eight, and Harper Willow, five, are struggling to come up with a name for their unborn baby, as they have already used all of the names they liked for their eldest girls.
Dave recently revealed that he had passed on his love for music, particularly the Beatles, to his children.
Speaking at the CBS special, 'The Night That Changed America: A Grammy Salute to the Beatles,' on Sunday night (09.02.14), the 45-year-old star said: "I can honestly say that if it weren't for the Beatles, I would not be a musician. From a very early age, I loved their groove and their swagger, their grace and their beauty, their dark and their light. The Beatles knew no boundaries and in that freedom they seemed to define what we now know today as rock and roll for my parents, for me and for my daughter too."
Before performing a cover of the group's hit 'Hey Bulldog,' he added: "The song I'm proud to play with these great musicians, from the 'Yellow Submarine' soundtrack, is not one of the Beatles greatest hits, but to me, it's a quintessential Beatles rocker. This is for my Mom's favourite band, my favourite band and now my daughter's favourite band."