Yep, I really am doing a triathlon – I am going to swim 400m, cycle 10km and run 2.5km in and around the London docks on 27 July. If I say it enough times I might even start believing it soon.

I'm doing this to hopefully raise lots of money for Arthritis Research UK. I was diagnosed with psoriatic arthritis in 2011 and for most of that year was in pain every day and exhausted if I walked for more than about 10 minutes. I struggled to work, have a social life, do normal things like clean my flat and go shopping. It feels like an absolute miracle that today I am able to even think about doing a triathlon. I want to celebrate that, make the most of being in remission, and most of all do this for all the people I've met (and the 10 million other people in the UK who live with arthritis) who are still in pain and might not ever get to do something like this.

I am choosing the beginner triathlon, not doing an ironman! I've worked up slowly to being as fit as I am now, starting really small last year with adding in an extra 2 minutes walking at a time. Even still, this is going to be a challenge! I've got lots of training to do between now and July – and it will be knowing people are supporting me that gets me through it, so thank you for visiting this page.

Anything you are able to give will go a long way – I won't try and explain all Arthritis Research UK's work as they obviously do this best at www.arthritisresearchuk.org, but I can sum it up by saying lots of their projects could make a big big difference. I've seen arthritis affect so many people, of all ages – I know two people who've missed uni to have hip replacements, have met families who've watched their toddlers in pain, and seen my mum go through three operations – so I know the work they're doing to develop better treatments could change a lot of lives.

It means a lot to me that you're thinking of supporting me – thank you!

Melanie xx