When I was in my early teens, my (second or third) cousin Mark O'Keefe developed leukemia. He fought and fought and fought - the kid had no quit in him. We played in rival basketball teams in the same competition, and I don't think my team ever beat his. He was a determined and talented player, and he loved the game.

As the disease progressed, he was no longer able to play, but he became his team's coach, wheeled in on a hospital gurney for matches, and winning more often than not. The next youngest coach in the competition was a decade older. Mark fought, and he fought, but in the end, there just wasn't enough fight to be had.

We were of an age, so we often hung out together at family gatherings, and he was just a regular kid off the court. We weren't that close, but I liked him and respected him.

All the years he should have had - all the games he should have played - the life of a boy and a man. Who knows? Maybe he was good enough to have gone all the way and won gold for Australia. Maybe he just would have been decent and kind man. We'll never know - but he should have had that chance. Everyone should.

It's for him, and for all the other kids whose lives are being tragically cut short, that I'm participating in this Challenge.

Because right now, cancer is the largest single killer of children from disease in Australia – and kids should be living life, not fighting for it. And so I am riding and raising funds to support the Children's Medical Research Institute to continue their work into the prevention, diagnosis, treatment and finding a cure for childhood cancer.

Please support my challenge by making a donation through my fundraising page to give these kids the brighter futures they deserve.

Thanks for your support.