EVENING Post sports reporter Stevie Roden is to compete in the London Triathlon this August, and he will be sharing his experiences in the newspaper and in a weekly, online blog. Here he explains why he took up the challenge...

WHAT was I thinking? Usually when I glimpse an advert in a magazine and think 'I might try that', it comes to nothing.

But within a couple of weeks I had enrolled for the full London Triathlon.

And after spending £78 to enter and £200 on a bike and other gear, there is no going back.

Once that payment had been sent, a sudden shiver went through me as the reality of what I had committed to hit home.

It was the start of 2009 and I had seven months to get myself in tip-top shape.

I have never done anything on this scale – no marathons, nothing.

As a kid I did a five-mile fun run, and I once came last in the 25m breastroke at Sutton's old baths while at primary school.

Since that embarrassing day, my experience of swimming has been little more than a few lengths for a bit of fitness down the local pool.

As for cycling, I have a mate from school called Phil Dixon who went on to become the British mountain bike champion. But that's about my only association with anything on two wheels.

So the prospect of a 1.5km open water swim, a 40km cycle around the capital and a 10km run is a more than a little daunting.

Football has always been my sport, and more recently a leisurely game of golf now and again.

Truth be told, I fancied a challenge – and clearly, not just any challenge. I could have entered the half triathlon, but I knew if I did I could take short cuts over the next seven months.

With a full triathlon to train for, there can be no missed weeks. I can't forsake going out for a run just because it is freezing cold and snowing – not unless I want to risk not being able to finish.

It is a way of keeping myself disciplined, a real reason to watch the diet and cut down on the beer.

And more importantly, I want to prove something to myself.

Back in the summer of 2004, a few days after my 24th birthday, I was diagnosed with rheumatoid arthritis. Like many others, I knew nothing about it.

Unaware what was wrong, I had gone from a healthy young lad to weeks of severe deterioration. On occasions I was unable to get myself out of the bath or pull my socks on.

It took endless visits to doctors, blood tests and specialist visits before we finally got to the bottom of things.

Rheumatoid arthritis is a condition where the immune system attacks itself, and when it flares up, it can affect all the joints, not just one. Usually it affects people later in life.

Over the course of a year or two, the right balance of medication was found to control it, and in general I have been able to go about my life as normally as possible.

Who knows what the future holds but at present, I have never felt better.

And after reading the stories of others, I felt it was time I proved to myself I could do something I never thought I was capable of, even before I my diagnosis.

Already I am in my sixth week of training and feeling great, losing the best part of nine pounds since Christmas.

Five days a week I am training around work, building it up each month to the big weekend of August 1-2 in London.

I have a couple of half triathlons pencilled in for April and May, trial runs to see how far I have come – and how far I still have to go.

It hasn't been easy to start with, and it will only get harder.

But it is all for a good cause: The Wish Upon a Star charity, based in Nottingham, does a wonderful job helping dreams come true for sick and terminally ill children.

Now I am pounding the streets, doing endless lengths in the pool and putting in miles on the bike out on the roads of Notts and Derbyshire.

There are no lie-ins for me – any spare time seems to be taken up with triathlon-based activity.

Hopefully along the way I will be able to bend the ear of a few sporting stars in Notts for top tips and advice to help me develop in time for the big day.

Feel free to catch up with my progress in my weekly blog at www.thisisnottingham.co.uk, and in the Evening Post for what I hope will be a light-hearted insight into how my preparations are going.

I am sure it will be a rocky, tiring journey. But hopefully it will be a rewarding one for me and Wish Upon A Star.

To sponsor Stevie visit www.justgiving.com/stevieroden

American-based sports giant Under Armour have backed Stevie in his quest to complete the London Triathlon and raise cash for Wish Upon A Star by agreeing to become his official sponsor.

They have provided him with a whole range of their latest hi-tech training gear to help in all weathers, and a new tri-suit for the race itself. For more information visit www.underarmour.com