Between now and 18 August I have to shed over a stone in weight, get down to 11 stone 6 and learn how to race a racehorse.
There will be regular updates here and at www.matthewhancock.co.uk
I'm taking part in the Newmarket Cavalry Charge - the first ever charity race at Newmarket's July Course, raising money for Racing Welfare and the Household Cavalry Operational Casualties Fund.
It's going to be a great day out so come to watch - and press the button to donate.
You can see more details about the race at: