CYCLING/Tour de France: The article was headed "50 Sporting Things to Do Before You Die" and my eye was caught by one event in particular: riding a stage of the Tour de France. Called L'Etape du Tour, each year 8,500 amateurs from all over the world sign up for this public stage of the famous race.

I signed up months before they revealed this year's featured stage. The day the details were announced, I received an e-mail from a friend who has a poor grasp of French. He couldn't understand much except two important, and somewhat scary, details: the route was 178km and it was in the Pyrenees.

The route of the L'Etape du Tour would follow tomorrow's Stage 16 in searing July temperatures, just one week before the Tour itself would tackle the stage. From Mourenx to Pau, it features the legendary tour climbs, the Col de Marie Blanque (1,035 metres) and the Col d'Aubisque, which at 1,709 metres is 700 metres higher than Ireland's highest mountain, Carrauntoohil.

My first reaction was fright when I realised the enormity of what was ahead: 115 miles over 3,000 metres of climbing with the temperature over 30 degrees, and all to be completed under 10½ hours. Failing that, I would be swept up by the broom wagon and eliminated. My next reaction was to begin training, hard.

Last Monday, after a few hours of poor sleep, the alarm clock rang at 4am. I faced into a breakfast of three bananas, a pear, two energy gels, an energy bar and a couple of tea cakes. It felt quite bizarre to be applying sun cream before riding off into the dark of the night to the start line.

A little over one hour later I was feeling very intimidated as I waited for the start, surrounded by thousands of well-toned, tanned and serious-looking cyclists. My only comfort was that I'd shaved my hairy Irish legs a few days earlier so I wouldn't look like a complete novice.

At 7am the buzzer sounded. It took 15 minutes for the thousands of cyclists in front of me to move their way slowly past the start line and out of Mourenx. The first 50 kilometres were mostly flat, and I easily achieved my objective of getting over the first climb, the Col d'Ichére, in three hours.

As I approached the base of the day's first major challenge, the Col de Marie Blanque, the early morning sun was rising fast and the temperature was hitting 30 degrees. The sign at the bottom said "Summit 8km". With every passing corner the road just got steeper and steeper. On the sign indicating "4 kilometres to go" someone had painted "welcome to hell". How right they were.

My breathing was getting very tight and I had to stop before I collapsed. Two young French boys were scooping water from a mountain stream and dousing anyone who asked. I rode towards them, and poured two full litres of it over myself as I tried to regain my composure.

Moments later I was heading for the summit, but my time was leaving me close to elimination. I sped up on the decent to reach the 94 kilometre elimination point at the picturesque town of Laruns with just half an hour to spare. I knew the broom wagon would be circling close for the rest of the day.

I found myself at the base of the 17km Col d'Aubisque. This was what I'd been training for more than a year to conquer. I still felt reasonably fresh, but knew it would take everything I had to get to the top. The first six kilometres were passed without much trouble, but then the heat became more and more unbearable. Cyclists were dismounting everywhere and lying in the shade at the side of the road. All I wanted to do was lie down and join them, but something kept me going.

My water was running out fast and I began to panic. I could see a mass of bodies stopped on the road ahead. Someone had opened a fire hydrant and the water was gushing out. What a relief. I got one last refill and a cold shower before my final assault on the mountain.

As I inched towards the top I could see the timing wagon close behind me. I would have to make up some serious time on the descent if I was going to avoid elimination. From here it was just a gentle climb up to the top of the Col du Soulor before a dangerous, 40 km descent into the valley below.

As I faced my bike for a nerve-wracking hour of descending the mountain, I thought to myself, "I don't like climbing, and I don't like descending, what am I doing here?" My wife got me a heart rate monitor for Christmas and I had to stop using it when all the analysis revealed was that I was always on the verge of a heart attack while descending.

Half-way down I saw a timing car in the distance with a man standing behind it waving his arms indicating to slow down. My heart sank. Was it the elimination car I had feared all along? As I slowed on my approach, I saw the blood-spattered body of a rider who had mistimed a bend. Thankfully, I was still ahead of the broom wagon.

As the road levelled out I checked my watch. I had two hours to spare and it seemed I would definitely make it back now, barring a disaster.

Moments later, my back wheel began to hiss violently. I had never got a puncture before. My initial calmness soon evaporated when it was obvious that I wasn't going to be able to fix it myself. My gentle calls for help to passing riders soon became hysterical until a very decent French man named Jacques stopped and got me on my way.

One last check of the watch. I had just enough time to get back. I passed under the one kilometre sign and up the steep incline into the square in Pau, where cheering crowds awaited.

Nine hours and 54 minutes and in 7,165th place, just 30 minutes ahead of the broom wagon.

Tired, but elated.