A non-swimmer who couldn't cycle and had never run competitively, Paul Pierce faced the biggest challenge of his life: competing in a triathlon

When my colleague Ben suggested I take part in a charity triathlon in America three years ago I had three solid points for refusal: firstly I couldn’t swim; secondly I couldn’t run. And thirdly I couldn’t ride a bike.

Fast forward 18 months later and there I am…in freezing cold water in San Francisco Bay wondering to myself: how on earth did I get here?

It’s all surreal when I think back. The driving force behind the triathlon was a fundraiser’s for Ben’s son Charlie. He has a rare blood disorder related to Leukaemia and he came up with the winning idea of pushing me to my limits as a good way to raise cash.

At first it seemed so improbable, so impossible that I turned him down point blank. But I’ve always been up for a challenge and the more I thought of it the more it bizarrely appealed to me.

I also realised it would be a brilliant fundraiser – so I pitched it round the idea that not only will I learn to run, cycle and swim but I’ll also compete in a triathlon.

At first it seemed so improbable, so impossible that I turned the challenge down point blank

It wasn’t as hard as I thought. Swimming was most difficult – yet my coach maintained I was one of the strongest beginners he’s ever met.

Running was a big challenge. As part of the triathlon I had to run 8k, mostly up hill. That was after the swim. But I completed it and, contrary to my own negativity, came in a respectable 121 out of 262 competitors.

Most of all, that event has given me huge motivation to keep doing greater challenges. Since then I’ve done the Three Peaks Challenge for Help for Heroes, the Tough Mudder and now I’m training for Iron Man – a gruelling 2.4 mile swim race, 112 mile bike race, and 26.2 mile marathon.

I’m not being dramatic when I say charity fundraising has changed my life. I’m an engineer by profession – I’ve worked inside all my life and though I’m on my feet all day I’ve never been very fit.

Now I class myself as ultra-fit. I swim twice a week, cycle to work and run twice each week. Fundraising gave me the motivation – it still does. I’ve raised quite a few thousand all told.

The first triathlon alone raised over £15k and thankfully Charlie is still with us, having received treatment in the States that has enabled him to lead a near normal life.

I don’t care about age – I never think about it despite the fact I’m getting well into mid-life. I just want to continue to take on greater challenges and get fitter and faster. And raise money for good causes while I’m at it.