Irish long-distance runner Sonia O'Sullivan will find herself in unusual surroundings at this Sunday's BUPA Great North Run in Newcastle. She will be the very last competitor to start the world's biggest half-marathon, behind over 54,000 professionals and amateurs, and is aiming to overtake as many runners as possible. The multi-medal winning athlete thought up the challenge to raise money for UK blood cancer charity Leukaemia & Lymphoma Research and Childrens Leukaemia Association at Cork's Mercy University Hospital, Ireland. O'Sullivan, whose many achievements during her career included 5,000m silver at the 2000 Olympic Games, is more accustomed to leading the field and she's asking people to donate money to her chosen charities for every runner she overtakes during the 13.1-mile race. A pound per person would be amazing a penny per runner would be really great. She said: "I'm not sure how long it will take me - to get past the 1000's of runners, which I'm not used to. I aim to overtake as many runners as I can and this will encourage more people to sponsor these two great charities." Thanks for visiting my fundraising page.

Donating through Justgiving is quick, easy and totally secure. It's also the most efficient way to sponsor me: Leukaemia & Lymphoma Research gets your money faster and, if you're a UK taxpayer, Justgiving makes sure 25% in Gift Aid, plus a 3% supplement, are added to your donation.

So please sponsor me now!