Helen Skelton's new Polar challenge for Sport Relief 2012

Over the last few months I have snarled: "Why am I doing Sport Relief again?" Not because I'm being mean, but because I have been, at times, utterly miserable when I've done it before.

One of those times was on an Icelandic glacier, 48 hours without a toilet, real food and in the middle of a blizzard so bad I could barely see my hand in front of my face. I am hoping it won't be as bad in Antarctica but in truth it could well be worse.

For Sport Relief 2012 I am going to attempt to get to the South Pole, covering over 500 miles by kite, by ski and by bike. No one has used a bike to get to the South Pole before, plenty say it can't be done so of course that's the method I would like to use. The weather and the terrain will determine how we travel each day.

I get asked all the time, why? Why give up Christmas, risk frost bite and hypothermia spending 16 hours a day in temperatures that could be as low as minus 50. Because that's nothing compared to what some kids in the UK deal with every day. I have met children through Sport Relief who make me realise I have absolutely nothing to complain about. It's because of them I won't give up.

But why think these things up and do it in the first place? Because I have a unique job in which I don't have to do paperwork or go to meetings. All I have to do is excite kids about the world. I don't expect every kid to climb Everest but I hope if they see me turn a struggle into a triumph they might realize that if something is hard it's not impossible.

The Polar programmes are going to be the first in a new series of Blue Peter specials. We're going to be moving to a Thursday next year, running all year round. In the near future it means we can get to more events happening over the summer in the UK. In the longer term I am hoping the flexibility means I will be able to persuade the powers that be to let me go off on another expedition and up the ante even more. Hopefully I will be on the first show of the new year live from Antartica.