David Tennant is one of a number of celebrities to wish Davina McCall good luck in the penultimate day of her unbelievable challenge for Sport Relief.
In the Beyond Breaking Point BT Sport Relief Challenge, Davina has spent the week travelling between Edinburgh and London entirely under her own steam. That's over 500 miles of running, swimming and cycling, and in the most appalling weather conditions. It's all to raise money for this year's Sport Relief to help change lives both in the UK and abroad.
David, filmed late last year on location for his Sport Relief trip to Sierra Leone, urges Davina, "If anyone can do it you can. You're a better woman than me. Good luck!"
Other famous faces in the clip include impressionist and actor Debra Stephenson, radio presenter Danny Baker and dancer Louis Spence.
Watch the clip here:
Click here to find out more about Davina's challenge and to sponsor her
Sport Relief 2014 takes place across the weekend of the 21st - 23rd March, and you can join in by taking part in the Mile, the Cycle or the Swimathon or perhaps coming up with your own fundraising idea. The money raised by the public is spent by Comic Relief to help change the lives of some of the poorest and most disadvantaged people both at home in the UK and across the world. More information about how you can get involved can be found on the Sport Relief website. And don't forget the live TV extravaganza on Friday 21st March where you'll be able to find out how other celebrities, including David Tennant, have contributed to this year's appeal.