The Difference Between the Physical and Mental Race Wall

Two Walls, and Only One of Them Is Coming for You

You'll have heard about the wall. It's one of the few bits of marathon folklore that's made it out of running and into ordinary conversation. People who've never run further than a bus stop know that marathon runners hit a wall somewhere around mile twenty and that it's supposed to be awful.

Here's the thing nobody talks about, or really tries to differentiate. There are two walls, they're completely different, and most runners get them mixed up.

One of them is physical. Your body genuinely runs out of fuel and slows you down whether you like it or not. The other is mental. Your legs are working perfectly well and your brain is doing everything it can to persuade you to stop.

The good news, and I mean this, is that the physical one is largely avoidable and most of you will never meet it. The mental one turns up for everybody, including people who've run twenty marathons. It's the one worth preparing for.

The Physical Wall

Your body stores its preferred fuel as glycogen, which is carbohydrate held in your muscles and your liver. You've got roughly ninety minutes of it at a decent effort. After that you're increasingly running on fat, which works, but converts to usable energy more slowly than your legs would like. The body uses a combination of fuels depending on how hard you are working.

The physical wall is what happens when that store genuinely empties. It isn't a feeling. It's your body applying the brakes to protect itself. Runners describe legs that simply won't do what they're told, a sort of fog, and a pace that drops whatever their head has to say about it.

It comes from three things, usually more than one at once:

• You haven't built the endurance. The body hasn't had long enough to get good at using fat as fuel, which is a large part of what all those long runs are quietly doing.

• You haven't fuelled during the race. Gels aren't magic beans. Their job is to slow the rate at which you empty the tank, not to give you a boost.

• You went out too hard and burned through the fuel faster than you planned to.

I'll be honest with you about how hard this is to do by accident. To hit a genuine physical wall, you'd have to ignore your fuelling plan, ignore how you're feeling, and ignore more or less everything we spend the winter talking about when we coach runners. Most runners who think they hit the wall didn't.

They had a very bad patch, which is a different thing.

So: the physical wall is real, and avoiding it is what the long runs and the gel practice are for. If you do those, the odds are you'll never find out what it feels like.

The Mental Wall

This one is a different animal entirely.

Your legs are “fine” (they are sore but they will work). Your fuelling is fine. And somewhere in the second half of the race a voice starts up, gently at first and then rather less gently, making a very reasonable case for stopping.

Do we actually need to do this? Wouldn't this be easier if we walked? What if we sat down for a bit? What if we had a nice coffee and pretended we never wanted to run again?

That voice isn't weakness and it isn't a sign you've done something wrong. Before a certain point in the race your brain's job appears to be getting you to do as little as possible, and it makes its case surprisingly well.

Two things are worth knowing about it.

It comes in waves. Discomfort in a marathon doesn't climb in a straight line. There'll be a stretch where you genuinely think you can't take another step, and then it eases. Half an hour later another one arrives with a different argument, and that eases too. When you're inside one it feels permanent. It isn't. It might take ten minutes, it might take twenty, it might take a couple of miles, but it passes.

Race day is not your long run. This one surprises people. When your plan says a hundred and eighty minutes, your brain signs up for a hundred and eighty minutes, and at the end of it, it clocks off. That's the deal it made. Which is why running an extra ten minutes on a long run feels so disproportionately grim. On race day your brain knows the deal is 26.2 miles. It might not be thrilled about it, but it's agreed to the whole thing, and that changes what it's willing to give you. You can't simulate that in training, so don't try to predict race day from how you felt at the end of your twenty two miler.

What the Numbers Say About Going Out Too Hard

Here's where the two walls meet, because one mistake makes both of them far more likely.

You'll have heard someone suggest putting time in the bank. Run the first half a bit quicker than goal pace, build a cushion, and spend it later when things get tough. It sounds sensible. It's the most expensive piece of advice in running.

We went through twelve years of London Marathon results, 502,443 finishers, and measured every runner against their own splits rather than against anybody else. The pattern doesn't wobble.

Almost everybody slows down. Ninety four percent of those finishers ran the second half slower than the first. Only about one runner in eighteen managed an even or a negative split.

And the slowdown gets bigger the longer you're out there. Sub three hour runners lost around three and a half minutes in the second half. Runners finishing between four and four and a half hours lost about a quarter of an hour. Five to six hour runners lost half an hour, and the six hour plus group lost well over that.

What the numbers can't tell you is how quickly each of those runners would have finished if they'd held back early. But when nineteen out of twenty people are already slowing down, "go out a bit quicker and bank some time" is advice to do more of the thing that's already going wrong. Time in the bank isn't a cushion. It's a loan, and the second half is where you pay it back.

The Tipping Point

Now the bit I actually enjoy talking about, because it's the part almost nobody warns you about and it's the best thing in the race.

At some stage, the argument in your mind stops.

Something unlocks. It's as though your brain finally goes: fine. I can see you're being stubborn about this. Let's get to the finish then. A bit of energy comes back that you had no reason to expect. The finish line stops being theoretical and becomes a real place you are actually going to arrive at. You start to believe it.

I can't tell you when it'll happen to you. It moves about depending on the runner, but somewhere between eighteen and twenty four miles is the usual window. It comes earlier if you're lucky, later if you're not, and as a rule it comes later the longer you're out there, which means if you're running a slower marathon you may be waiting a while for it.

That's the whole job, really. Everything before the tipping point is about getting yourself to the tipping point. After it, the race comes to you.

Getting Yourself There

None of the above is much use without something to do in the moment, so here's what actually works when the voice starts up.

• Break it into small pieces. The next gel. The next drink station. The next mile marker. Your brain gets a little reward each time you tick one off, and a 0.2 mile problem is easy where a 26.2 mile problem is impossible. I've had marathons where the deal was getting to the next lamppost, at which point I was fully entitled to reconsider all of my life choices. You get there, and you find you can do another one.

• Have a phrase ready. Something short you can repeat with your breathing. It works because it gives you something specific to do instead of standing there arguing with the discomfort.

• Change the focus. Count to a hundred. Count backwards from a hundred, which is much harder than it sounds and therefore better. Think about the snack in your kit bag. Anything that isn't the running.

• Smile. Genuinely. It shifts how the brain reads discomfort, and you'll look considerably better in the photographs.

• Have a B and a C goal. If your A goal slips away at mile eighteen and there's nothing behind it, the head checks out and the damage is far bigger than the minutes you just lost. I've watched a runner on for 4:05 finish in 4:30 purely because sub four had gone and they had nothing left to chase.

• Expect the discomfort and let it be normal. Legs sore at mile twenty two is not a sign something has gone wrong. It's a sign you're doing the thing. Right where I should be.

  
  

One Last Thing

Walking doesn't diminish any of it. Not one bit. If you walk the hills, or take a walking break at every mile marker, or end up walking more than you planned, you are still a person running a marathon.

And whichever wall you're worried about, the honest answer is that the preparation deals with most of it. Fuel properly and build the endurance and the physical one stays away. Pace it sensibly and know what the voice sounds like, and the mental one becomes something you get through rather than something that gets you.

Then you find the tipping point, and you get to the bit that makes the whole winter worth it.

Training for a spring marathon? The pacing and the fuelling are the two things that decide which of these walls you meet, and they're both easier to get right with someone building the plan around you.

Drop us a line and we'll put together a block that gets you to the start line fit, fresh and ready.