What I did this weekend by Tristan, aged 35 and a quarter.

It took twenty five hours and thirty one minutes to complete Trailwalker, and then about the same time again to appreciate what I'd gained and learned over the past few months, and from the event itself. Yesterday it all seemed very different but a couple of baths, good meals, lots of water and sleep have put it all into perspective once more.

I'd been told by a friend before the event that it helped to think about why you were taking part - not just about the charity cause, but the real reasons, and to have these to hold on to when the going got tough. When we set off I thought it was all about the money we were raising, proving something to myself and not looking a fool for quitting. In the end, this was why I took part, but my team were why I finished. We were lucky to have an incredible support team who - without wishing to sound like an Oscar acceptee - gave up sleep, time and effort to help us through it. And I had three teammates without whose encouragement I'd have never finished.

Arguably we hadn't prepared enough. I'm fairly fit and for the past few months we've walked at weekends while I ran and cycled during the week to get ready, but I didn't realise how physically demanding walking for over twenty four hours could be. Training for The Big One was superb though: I spent many spring and summer weekends discovering the South Downs while enjoying meandering conversations and sharing jokes with three of the nicest people you could wish to meet, often with partners, children and friends in tow. But I don't know how you can prepare yourself for carrying on when your body and mind says "no more" and it's only your will pushing you on. Maybe it's through actually taking part that one learns how to cope, and for that experience I'm grateful.

It's been interesting reading how Lloyd and Alick view the walk in retrospect, for me also there were three distinct stages: up to The Bees, the night, and the morning after.

Up 'til The Bees it had been a splendid adventure. The walking had been long and arduous, but the weather could not have been better. It was warm without being hot, with a cooling wind and a crisp, clear view to the North Downs on one side and the Channel on the other. The exercise made the pork pies, tomato soup and cheese sandwiches taste like the best fare from a posh restaurant. The scenery, sunrise and sunset were beautiful, especially the sunset at the end of Saturday which bathed the vista in gradients of orange, red and purple over more than an hour. And then from nowhere swarms of bees rising out of hawthorn bushes, intent on twisting our mellow. In the end we ran and jogged the best part of a kilometre to escape them, which was tiring and frighteningly distracting and demoralising. The sun went down and suddenly the fun disappeared as the light died. From then it was a slog to the next checkpoint at Devil's Dyke.

The night, with its increasing load of sleep deprivation and disorientation was odd. Fatigue had set in, the uneven ground was difficult to navigate and my shoes were shredding my feet. Having trained in walking boots alone, I'd stupidly switched to my runners half way through the course and by the time we reached the checkpoint at Jack and Jill I wanted to stop. But as we left for the next yomp I dropped in behind Lloyd and let Jimmy Cliff and New Order on the iPod distract me from the hurting. We made good time through the night, alternating the role of pacemaker to the end of the hardest and longest stage, arriving in Kingston where Caroline met us with tea and warm bacon sandwiches. By this point I was so spent that I couldn't really tell what was in the sandwiches but the nourishment they gave helped enormously and we set off for the penultimate checkpoint.

As dawn broke and we tackled the closing stages my knee hurt and perversely I found myself hoping for uphill stretches since going up a steep gradient was preferable to going downhill. We kept moving and eventually emerged from these last two stages, complete with Biblical thunder storm, to a grotty path behind a housing estate within sight of the racetrack. And then they made us walk round the damn track for almost kilometre to the finish line. Pure torture. Like Alick, I was nearly in tears at the end - other finishers actually were.

I didn't really want the medal at the time, I just wanted to go home and rest, but now it's all sunk in I'm proud of what we did. We finished a helluva course, helping each other through, and in doing so I learned a lot about myself and my team.

So, all that's left is to thank the many people who sponsored us for two very worthy causes, the Ghurkas whose sincere applause greeted us at every checkpoint, the support team whose smiles, food treats and tea kept the hope up, and the good friends with whom I am honoured to have shared this experience.