La FilippideForty-two kilometres without knowing what time it is.

I've run it twice. The first in 3h42', the second in 3h24'. But I only learned those two numbers at the finish line, and that is the whole point.

It's held in early August in the province of Ragusa: you start from the old railway station of Chiaramonte Gulfi, at eight hundred and thirty-three metres, and forty-two kilometres later you finish far below, in front of Inspector Montalbano's house on the beach at Punta Secca.

Except every four years. In Olympic years the finish moves to Kamarina, a Greek colony founded on that coast in the sixth century BC. A race named after Pheidippides that ends inside a Greek site every four years isn't an organisational detail: it's somebody who thought carefully about what they were doing.

The rules describe it as a race to be run in a state of temporary spatial and temporal isolation. In practice: no measuring instrument of any kind on your body, on pain of disqualification. And since taking off your watch achieves nothing if the course then tells you where you are, they removed the external references too — no kilometre boards, and aid stations deliberately placed at irregular intervals so you can't count with them.

The first two hours

Something irritating happens. Your hand goes to your wrist on its own. Not to check the pace — to know that you know. It's a tic, and you only notice how many times a day you do it when there's nothing left to look at.

Then there's the background noise, which is worse. Your head keeps doing the arithmetic by itself: estimating, correcting, wondering whether it's going too slow. And it can't answer, because it outsourced that ability twenty years ago to a three-hundred-euro object and hasn't exercised it since. It's like asking someone for a phone number that's been in their contacts for a decade.

Then, at some point, it stops.

And what's left is the strangest thing that's ever happened to me while running: you're just going. In August at half four it isn't pitch dark: you can't see much but you can see, and a head torch isn't needed. The only thing written on the ground is an arrow at each junction. Otherwise: your breathing, the road, other people breathing near you. No information at all. You don't know whether you're doing well, so you're not doing well or badly: you're doing.

It is precisely the only condition in which every human being ran for two million years. To reproduce it today you have to go to Sicily.

And something has to be said about how the ban actually works, because it isn't what you'd expect. Nobody searches you. There's no wrist check at the start, no metal detector, no official patting you down. The rule is formal — cheating means disqualification — but the people enforcing it are the runners themselves. You watch each other, and nobody cheats.

You don't know if you're going well, so you're not going well or badly. You're going.

The sea is not the finish

First things first: the race gets described as all downhill. It is emphatically not all downhill. There are some proper little climbs, short and vicious, and you don't know when they're coming. In a normal marathon you know the elevation profile by heart: you've known for weeks which kilometre starts to hurt and you've already decided what you'll do there. That's half the craft. Here you don't have that half.

But the real blow is something else, and it's why this race teaches you something instead of just hurting you.

At some point you see the sea.

And your head immediately does what heads do: it closes the account. That's it, we're done, last push. The sea is one of the two spatial references the rules allow you — the mountain and the sea — and you take it for what it looks like: the finish.

It isn't. The course starts winding between the big greenhouses, and it winds there for kilometres. It's round the next bend. It isn't. Then it's round the one after. Also no. You go on like that, with no idea how much is left, the sea sitting there and never really getting closer. The first time I blew up and walked.

The Kamarina edition was worse, and worse by design. I see the sea, I tell myself last push — and instead a climb starts. Then you drop towards the cliffs. Then you climb again, up to the temple.

It ends when it ends. Not when it looks like it does.

And this is where I understood what the watch is actually for, which isn't what I thought. In the closing kilometres GPS isn't there to make you go fast: it's there to hold you back. Knowing you have six kilometres left and not two is what stops you launching when you see the end.

Without it, you have to do that job yourself. You have to stay focused precisely on not knowing where you are, and hold yourself back at the exact moment everything is telling you to go. It's the hardest thing of the day, and it's the one thing I took home and still use.

The thing I didn't expect

I didn't run slower. The second time I ran eighteen minutes faster than the first — on a kinder course, it should be said — without knowing my pace at any point along the way.

Which says something uncomfortable about the watch: it isn't what makes you fast. It's what tells you how fast you were — and it does that so well that you end up trusting it more than you trust yourself.

Then you finish, and the time is there: the race is properly timed and you find out at the line. That's exactly as it should be. It's that I had lost the other measure, the internal one, and hadn't noticed — because a thing you don't use doesn't feel missing. It just disappears, and in its place sits a tool that works better.

Where the race and the manifesto disagree

A point of honesty, because it would be convenient to leave it out. The rules describe the race as a personal challenge against yourself, and in the manifesto we argued that this is the hardest trap to see: an account between you and you never closes.

That still holds. But La Filippide does something almost nobody does: it takes away your means of keeping score. There are no age categories, no commercial sponsors, no prize money and no goody bag. The first man and first woman get a cup and an olive wreath; from second to last, everyone gets the same medal and the same certificate.

If you've read the chapter on the tribe, you'll recognise the mechanism. It's the same logic that makes the !Kung insult the meat a hunter brings back: a device that stops effort from converting into standing. Here nobody calls it that, and they've probably never thought of it in those terms. It works all the same.

And then there's the matter of enforcement. A severe rule, nobody imposing it from above, and nobody cheating: the group regulates itself. That isn't an organisational detail — it's exactly how every society that ran out of necessity worked. The rules that hold aren't the policed ones. They're the ones a group has decided to take seriously.

The two races on Strava

They're there, and it's worth saying how. They were uploaded by hand after the finish: no GPS track, no pace graph, no heart rate. One line with a distance and a time.

That isn't a contradiction of anything written here. It's the opposite: we're on Strava too, we train off plans and we watch our paces like everyone else. The point was never to get out. It's that every so often you can do something else, and come back.

The rifle took away the chase. GPS took away the map. The watch took away the internal measure. None of the three gives it back on its own: you have to take it back by hand, and for a stretch — not for good.

Once. Once is enough to understand what you were measuring.