Most of you reading this will know me, but, just in case you don't, my name is Jonathan Gilbert (on the right in the photo).

I'm 25 and from Manchester, England, but I have been living for more than a year now in Buenos Aires, where I work as a journalist.

In Britain my friends and family call me Jon (or sometimes Gilbo), but people here struggle to pronounce that and they call me Shon.

I enjoy running, but I've never attempted a full 26-mile marathon before. It's going to be quite a challenge since I'm aiming to break the four-hour mark.

I'm rasing money for Citizens Advice, which provides a free service to help people tackle their problems, particularly legal and financial ones.

My mum has worked there for years and I grew up hearing stories of people facing eviction from their homes; threatened with deportation to countries where their lives were in danger; or struggling with debt.

I will also personally donate 25 per cent of whatever is raised to St Ann's Hospice, which looks after people in the Manchester area who are terminally ill.

I was so grateful for the way its staff cared for my grandpa last year before he died of cancer. I will run in his memory in a Bolton Wanderers shirt.

I started training in the first week of July, though I'm now easing off as the race nears, and the longest distance I have covered is 21.3 miles. That was back home in Manchester, but I have mostly trained in Buenos Aires, which is a real pleasure: through huge parks, down leafy boulevards, and along the river estuary where locals fish, and cook sausages and pork on barbecues.

I'm looking forward to it and I hope you can help me reach my target of £1,000.

Thank you, Shon