BY the second hairpin my heartrate monitor was having a fit.

By the third I had to put a sweatband on to stop salt flooding my eyes. Suddenly I felt overwhelmed - there were still 18 tortuous bends to go.

One of the greatest mountain climbs in the cycling world, the slopes of Alpe D'Huez are steeped in sporting legend.

The Alpe is an evil quantum leap from Bourg D'Oisans, a French Alpine riverside village, to a ski station summit at 1,860m.

In Britain a climb on a bike is usually short and sharp, a minute or so of grinding the gears. Not so in the high mountains.

There is no real way to train in Wales for an hour and a half of relentless gradient. I tried to be fairly fit and not too hungover, and picked some low gears. I rediscovered prayer.

There was plenty of inspiration a few days earlier when I saw the pros of the Tour de France suffer on the feared slopes.

An incredible crowd thronged the snaking road to cheer Lance Armstrong to win the stage. A week later in Paris he would celebrate his record sixth Tour victory.

Even if you're not into cycling the Tour is an unforgettable sight. Where masochistic folly meets big business, the Tour is the toughest endurance event on earth, and deeply rooted in the French psyche.

Families picnic by the roadside, waiting in the sun for the awesome colour, noise and pomp when the riders arrive.

Fans paint the names of their heroes on the road and so I rode over technicoloured shouts of Allez Virenque! Ullrich! Go Lance!

I was about halfway up, vaguely aware that the view next to me was biblical in its splendour, but dealing with too much pain in my legs to turn and look.

A cyclist drinking from a spring ran alongside me pouring icy water over my head - just like in the Tour.

A Dutch group stood outside their campervan and cheered me on. They'd been parked on a sunbaked bend for almost a week - spaces filled up four days before the Tour arrived.

I'd stayed at a nearby campsite with a pool, and our neighbours faced the Alpe in their own ways. An American couple in their 50s pootled up on fat-tyred mountain bikes. The guy behind us stormed it on shaved legs and a £4,000 race thoroughbred.

When we got tired of camp food we went to Bourg D'Oisans for French fare and kebabs. The town lives for skiing or cycling and also has plenty to offer walkers. But just being in France is fascinating: for the food, the ambience, the culture.

As I took the final hairpins the mercury hit 37C.

Tour workers dismantling crash barriers looked up as I dug deep, picked my way through the wooden ski resort lodges and put in a final, proud sprint for the line.

Up there among the snowy peaks, surrounded by knackered cyclists flushed with joy, I reflected on my new-found athleticism. It had taken me over twice as long, but I'd followed in the tyre tracks of my Tour heroes.

FACT FILE

* The Tour runs every July and takes in huge tracts of France, including the Alps and Pyrenees. The finish is always on the Champs Elysees in Paris.

* Some of next year's route has already been announced. Check www.letour.fr, L'Equipe newspaper or the English language guide to the Tour, sold in British newsagents from late May. They have precise arrival times and road numbers.

* Camping in France is easy but the Tour is hugely popular. Hotels get booked months in advance. Campsites fill up days before. It's easier to stay a bit further away and drive to the race very early on the day. Watch out for jams and road closures, particularly on mountain stages.

Best of all join thousands of others by camping on the route by the roadside. It's free and fun.

* I used a towbar-mounted bike carrier to get my bike there. Others opt for cheaper strap-on carriers or roof-racks. At famous climbs like Mont Ventoux bike hire is possible.