It might be a long way from Prestons but next weekend, Petra Velkovski will be walking to Bondi. In the City to Surf, that is.

Miss Velkovski has been exercising three times a week to prepare herself, but for her it's not just about completing the 14 kilometres from the city to the beach non-stop, it's about giving back to the hospital that helped her.

For four years, the Prestons woman, 21, was a cancer patient at the Children's Hospital at Westmead. She has been in remission for 2 years, and has decided to enter the race as part of the Kids Challenge, raising funds for The Children's Hospital at Westmead and children's hospice Bear Cottage.

``Having been a patient I have lost a lot of friends along the way and I would really like to help those who are now in need,'' she said.

``If everyone could help in some small way it would mean more kids would have the opportunity to have a chance at life.''

It's still not too late to join the City to Surf, on August 8. People can register to run or walk for a charity or just for themselves, at www.city2surf.com.au.