Alex Jones has said she might come across as an airhead on The One Show - but she's anything but.
The presenter, 36, who is preparing to climb the steep ascent of Moonlight Buttress, Utah, for Comic Relief, said her bubbly persona can give people the wrong impression.
"I probably sometimes come across as quite ditzy but underneath I can be quite determined and very focused," she said.
"As far as I'm concerned, it's not ditziness anyway, rather it's just a lightness of touch.
"I know people may say, 'Oh, that Alex, she's an airhead', but I think to myself, 'OK, you come and do my job and see how you get on with it!'."
Alex said she had managed to make the show "her own" after taking over from Christine Bleakley, who quit in 2010.
She added: "I like a good laugh and can be girly but, believe me, I still have a career plan. I'm conscientious and work my socks off to make sure I improve all the time."
Alex said she'd like to have children in future but is taking things one day at a time with insurance broker Charlie Thomson because her boyfriend of two years is likely to one day go back to New Zealand.
"I know Charlie will always hanker to go back to New Zealand for the outdoor lifestyle because he's not really a city boy," she said.
"The trouble is I can't see myself living there because I'm so close to my family. So he's nowhere near his family and I can't bear to leave mine," she said.
"It's not ideal, but we're not worrying about it, and just taking each day at a time."
Alex added: "A family when the time is right would be amazing, and if it happened we'll deal with that. But at the moment it doesn't feel the right time to step away from my career. And if for some reason it doesn't happen, I'll deal with that too. I know you can't have it all."
:: Sponsor Alex Jones at www.sportrelief.com/alex. Her climb will be shown on BBC One's, The One Show from March 17, 7pm.