Sir,

You can train for not much more than 50 hours to run a marathon in a respectable time - it's tough, but for many people, entirely achievable. In contrast, to race my first Ironman last weekend, I've trained something like 600 hours in the last year. That's early mornings, late at night, sneaking out from work at lunch for a run or a swim.

At times, the last thing you want to do is put your trainers on, yet you still do it. And then, after a few shorter races and after weeks of living like a hermit to lose an extra couple of kilograms, you find yourself on one of the nicest beaches you've ever been on. All around you are hundreds of other people who know what you've been through to get there. There's a man in front of you singing the Welsh national anthem as loud as he can. There's crowds lining the cliffs surrounding the beach, perhaps two or three deep. The lifeboat is practically on the beach and you wonder if you and 1,500 others will have to swim around it.

Whether you take nine hours or 17 hours, your body is going to hurt like crazy and your brain will at times scream at you to stop. Yet from the moment you walk onto that beach, life is a dream, because wherever you go on that 141-mile course you know that not much more than a metre away there's somebody to shout your name, somebody to tell you to keep going, somebody with a welcoming smile.

There were times on that course where that support brought tears to my eyes. Tears to the eyes of a grown man just because somebody I didn't know had given up a few hours of their Sunday to show their support!

To the people of Tenby and Pembrokeshire, I'm sure I speak on behalf of all those athletes when I say thank you. You made one of the hardest days of my life one of the most enjoyable.

Andrew Gwynn,

London.