Up the Ben and down again

Every September, a crowd of people gather at Fort William in Scotland to run up, and hopefully down again, Britain's highest mountain, Ben Nevis. Village sent Colin Murphy to join them

The Lochaber pipe band marches around the community sports field at Claggan Park, a small but enthusiastic crowd cheering. A round-topped, but imposing, mountain shadows them. Behind the pipe band, 400 or so men and women (much in the minority), in very little clothes, shuffle along.

The pipe band stops in front of a small viewing stand. A microphone crackles to life. "You're welcome to the 2005 Ben Nevis race."

Jonathan looks grim-faced. "This is it mate. Good luck." I do a last minute stretch. And then we're off.

Ben Nevis isn't actually in sight. It lurks behind the imposing hill in front of us, though about twice its height. It helps that we can't see it.

The day is perfect. Conditions at the top are good, we're told, clear visibility, 12-13 degrees, a light wind. Though we all carry bulging bums bags, with compulsory full-body cover – rain gear, hat, gloves – and a whistle. There's a "power gel" shoved into mine also, in panic.

The Ben Nevis race happens in September every year, and has been run on and off since 1895, when William Swan ran it in two hours 41 minutes. It starts just outside Fort William, on the sea inlet Loch Linnhe, winds its way up to the peak, and comes back down again in a roughly ten mile route. Starting at sea level means that the race covers every one of the Ben's 4,406 feet of altitude. The current record stands over 20 years, when Kenny Stuart won in 1:25. I hope to finish somewhere between the two – though I tell myself I'll be happy if I finish at all.

There is a mile or so of undulating road to the start. We clip along, energy finally dissipating the nerves, small clusters of people at the side of the road cheering. The morning has been spent shuffling nervously around Fort William, aggressively digesting breakfast and drinking sports drinks. The body is clearly relieved to be finally doing it, not just anticipating it – and surprised that, so far, it feels like a run in the park.

I try not to think of what's ahead.

We come to the end of the road. Uphill all the way now. It'll be good to reach this road again. There is a long stretch of winding stony mountain path taking us around the lower hill and to a bridge over a gully where we hit the Ben proper. The pace is steady. I seem to be in large string of runners ahead of most of the field but already well behind the leaders. People jostle past each other on the narrow path, watching underfoot, skipping over a stream, overtaking someone along a ditch.

There are small groups of people watching, holding out bottles of water, calling out the names of locals running.

A runner just ahead of me veers suddenly off the gently ascending path and starts climbing directly up. The runner behind him follows. I look up, and see a steady stream of runners pulling themselves up a steep stretch of mountainside and meeting the path as it curves around again at the top. Quick decision – I stay on the path. I'll save my legs. In British hill running, unlike in Ireland, there is no prescribed route – you just have to make it to the top and back again.

A little later, we come to a gully, with a stream. The runners ahead follow the path up stream to a stepping-stone crossing. But on the other side, the path doubles back again before heading on up the mountainside. I skip off the path, down the muddy bank, and pick my way across the stream on just-submerged stones. Scrambling up the bank on the far side, I've gained at least two places, and a pair of sodden shoes.

It's steeper now, and starts to get shingly. The path corkscrews up on a mixture of scree and mud. The pace slows. Every foot that hits the ground slides back inches, like running up a downward escalator. I sustain myself thinking, soon, you'll be running down this. But then I look down my feet and wonder, how on earth can I run down this.

Over a ridge, a sudden breeze hits. Or maybe a wind, it's difficult to tell what it should feel like – except that the marshals and assorted supporters standing around are now wearing hats and gloves and thick jackets.

I haven't seen anyone holding out a drink for a while, then I see a woman on the side with a bottle of Lucozade Sport. Drink! I gasp as I approach, aiming for her bottle. Startled, she holds it out – she's just a passing walker, not a race supporter. I throw back a mouthful, thrust the bottle back into her hands with a rasping thanks, run on. It is the sweetest thing I have ever tasted. I remember the taste all the way up.

Now it is steeper again. The pace has slowed, the rhythm changed. This is not running, or anything like it. This is clutching at clumps of grass or rock edges, dragging feet up behind, levering legs straight by pounding hands down on them. Everyone is bent double. There is no pace, no competition, just a long line of people concentrating on keeping going, on the next step. But I know, now, I'm going to make it up, and the thought of coming down sustains me.

A sign of hope – what looks like a man appears, coming down. He is shaped like a man, and in running gear, though clearly he is a goat. He skips amongst the climbers at an impossible speed, bouncing from footfall to footfall, and disappears beneath us.

But the summit is near! The incline slowly levels off, bodies straighten, try to run again, as we reach the plateau. Jonathan passes on his way down, shouts, "That's it lad, the worst of it's over!"

Then I'm at the peak. Of Ben Nevis. Of the highest mountain in the UK and Ireland. I try to look up, but stumble on a loose stone. For the minute or so I'm at the top, I steal a few surreptitious glances out towards the cloudless horizon, enough to confirm that there is not, indeed, any land higher. I've made it, so. This is one of only 60 days a year when Ben Nevis is clear, but I don't have time to look.

We hurl ourselves off the top again. I feel electric. No pain, little tiredness. A quick analysis of past race times showed that most people descend in half the time it takes to ascend. Jonathan and I make it up in less than 1:20 – on course for a two-hour finish.

And then people start to pass me. Though I'm fit, I'm out of practice on the hills, and my feet feel slow and hesitant on the rocks below. A steady stream of men bounce around, almost over me, as I pick my way carefully down. It's pissing me off.

Here, in Britain, this sport is called fell-running. "Fells" sound gentle, English, something that belong with dales and glades, in the Shire perhaps. Was there an Enid Blyton Five go Fell Running?

But this is not fell-running. This is lunacy. This is trying to run down an almost-vertical, scree-covered mountain. Feet barely land, picking themselves off the stones again before the stones slip from under them. Or land and slide down, surfing a small wave of scree. Or find a larger, fixed stone and break on it. I find a skiing movement works, using my body, not my feet, to turn, throwing myself into a succession of sharp turns that keep me going down, but give me some illusion of control over my speed.

And then it happens. The rhythm. Seconds ago, I didn't know how anybody could safely go faster than me, was braking on every stride. But suddenly, the brakes are off. I start to catch people, passing them aggressively. A runner just behind me goes to overtake as I swerve to avoid something, and we collide. We slide forward in a bundle, roll over each other and find ourselves back on our separate feet, still going downhill.

All pretence at restraint is abandoned now. A long line of runners come to the end of a steep descent, hit the path, and instead of turning to follow it, cross briefly, and hurl themselves over the edge again. This time, the surface is peaty and grassy, less scree. My feet go from under, and I slide some metres. That works – I spring to my feet and jump into another slide. I pass someone to my left, scrambling now, like a crab, my hands behind my back trying to keep the base of my spine away from any hidden rocks, feet searching out clumps of heather to spring forward a little further.

Then the going gets tougher. I fall. I fall again. I shout out, fear my ankle going. The ground is softer, so with every stride down, you have to pull your leg out of the mud again to send it down into the next stride.

And then it's gone. Where a quad muscle once was, just above the knee, pulling the legs out of bog and sending them downhill again, is nothing. Suddenly every step feels like a fall, legs buckling each time.

People are passing again. I'm wobbling. This is the last leg of the decent, on firmer path, more people cheering again. Nothing in my legs. The rest of me is fine – not short of breath, most muscles working, thirsty but not dehydrated. But the steps barely come. Constant near falls, then one that feels bad but I can't see any blood.Then it's the road again. I have to walk. Keep moving, pretend to myself I'm speed-walking. Out of pride, purely, I try to run a bit.

The sparse crowd are clapping, and the announcer calls out my name as I drag myself up into the field for the final lap to the finish. I shout myself around the track. The finish comes blurrily into view, though there is a crowd there and I can't quite tell where the line is.

I've made it. I stumble to the water table, drink three cups, pour two over me. Immediately, I need to pee. I stagger a couple of metres to a fence at the side and urinate into a hedge, holding onto the fence to keep standing. Then I collapse backwards. The grass is like a luxuriant double-bed and I sink into it. I listen for Jonathan, whom I overtook on the early part of the descent. Every inch of my body is sending fevered signals to my brain; most of them are pain, but flooding them all out is one greater, delicious feeling – relief.

After an age, I hear Jonathan's name, and look up to see him cross the line. He dropped back badly, and it seems a long time I've been lying here, ten minutes, maybe fifteen. We check our times later in the evening. Jonathan finished three minutes after me.

There is a river alongside the field, running down from the mountain, and I limp down to it, and in, in my shoes and shorts. It is knee high, like a deep bath. I lie back and look at the sky. It's over.p