I'm riding this race in memory of my dad who died of prostate cancer in 2000. I realised while he was dealing with his illness how vital good care is to cancer patients. One in two people get cancer and Macmillan are there to help.

My dad was a passionate follower of the Turf, and if he'd had his way I would have been christened Lester or Vincent, after the two greatest figures in 20th century racing. He took me to Sandown many weekends,  we were at Ascot the day Frankie Dettori won his 'Magnificent Seven'. and the Guineas at Newmarket was the last time we spent together away from his sick bed. There were also the "afternoon walks" as a small boy which involved endless hours spent waiting outside the local bookie while my dad did his business.  So my memories of him are tied up with racing.

I've ridden horses for films - I first learnt to ride for War Horse in 2011 -but this is a huge step up from that  as I've never sat on a racehorse before, and I need to lose some weight and get much stronger. It's going to take up most of my spare time until June but I'm taking it seriously.

Macmillan Charity Raceday is a fundraising collaboration between York Racecourse and Macmillan Cancer Support. The day of professional racing and fundraising has been held annually since 1971, raising more than £7 million in total for Macmillan and other charitable causes. For the last two years has raised a grand total of £500,000. This year, we hope to raise even more as the demand for our services continues to grow.