Over the last couple of years, running's become my default coping mechanism. It's how I start my weekends; it's what I do to calm down if I'm stressed or worried; it's a fun way of seeing the sights when I'm on holiday; it's how I clear my head. And from time to time, I've had minor injuries that have stopped me from running - a twisted ankle here... a shin splint there... Every time I have a twinge or ache, I try to remember how lucky I am to be well enough to run in the first place.

Rheumatoid arthritis (RA) affects around 400,000 adults in the UK, with around 20,000 newly diagnosed cases each year. And while many people with RA are well enough to continue to do the things they enjoy, there are also very many whose condition affects their normal activities... and that's just the stats for RA, not all the other types of arthritis.I single out RA because my mum Jayne was diagnosed with it in her late twenties, and lived with the condition until she passed away in September 2013. Like many RA sufferers, Mum rarely complained, and did her best to "get on with it". But I know how much it bothered her to struggle with things that most people take for granted, and that's why I'm running for Arthritis Research UK - in memory of my mum, and to support all those who are living with the condition.

A confession: it's not all philanthropic. I love running, and doing a half marathon is a personal goal. I'm very much looking forward to the challenge, and to visiting all the new places that I'll run through as I plan my ever more elaborate training routes. But as I run, I'll think of my mum, as I often do, and I hope the enjoyment I get from running can also be used to raise money and awareness for Arthritis Research UK.