marathon nutrition | The Rundown

by John Schrup

My good friend James wrote me an email recently. You all know James. Hot wife. Coaches for Rogue, knows a lot of stuff. Looks like he might have played an Amish dude in that Harrison Ford vehicle, Witness, from back in the day, except for the electric yellow Frees and the Euro-style glasses. Well, his beard looks like it was in the movie. He’s got one of those Amish beards.

Anyway, he wrote me an email while we were sitting next to each other in a meeting and suggested I write something for the blog on bonking. You know, hitting the wall? Screwing the pooch? Shitting the bed? (James himself has also written a great piece on the topic)

Maybe you’ve experienced it? If you’re a marathoner, at some point you have. If you haven’t, oh don’t you worry your pretty little head, you will. Oh, yes. You will. And there will be no mistaking it when you do. You’re doing your long run, or your race, or whatever and then it’s kinda like getting hit by a truck, except if the truck were made out of a planet.

Hitting the wall, or bonking, if you come from the le monde du cyclisme, is when the body runs out of ready available fuel. Glycogen is the form of carbohydrate that the body uses for fuel, and is stored mostly in the muscles and liver. When that is depleted…bonkity bonk bonk. The average person stores about 90 minutes worth of glycogen; a moderately trained person can go about two hours on the same amount of fuel. Back in the day, when they did studies with runners and fuel efficiency, the runners could make it about 18-20 miles in two hours, and then the wheels came off. That is where we get the mythological 20 mile “wall.” But also because 20 is a nice, round number. 19.27 doesn’t have the same ring to it. Neither does 18.6, unless you call it by its other name, 30K.

Since the dawn of marathon training history, we’ve done long runs to build mitochondria, capillaries, muscle strength, blah blah blah. And also to make the body more fuel efficient. Conventional wisdom would have you do, say, a 10 mile run first. 90 minutes, whatever. Then every week or every other week you’d add to that, slowly teaching the body to go farther and farther using your body’s own fuel supply. And at some point in the training program, you’d get up on a Saturday or Sunday morning to meet your posse for the long run and everything would be all fine and dandy, and then at maybe 15 miles, I don’t know, two and a half hours or something, you’d start to feel a little funny. A little sluggish maybe. You look at your watch. There are symbols there you recognize. Numbers. But you don’t know what they mean and you can’t figure out for the life of you why they are changing. You know you’re supposed to know, but you don’t know. And then maybe you trip over some stray air, and splat! You’re checking the pavement for cracks. Except real up close. Moving your legs is not only difficult, it becomes surreal when you think about the tunnel vision and that the part of your face where you put the water isn’t working the way you think it should.

But somewhere along the way, it was discovered that if you refuel on the go, you can make it to the finish line without looking like you got hit by that planet truck. Cyclists had been doing it for years. When I was a kid, I thought it was so cool to watch video of le Tour and there were guys eating ham sandwiches and pastries while climbing le Tourmalet or Alpe d’Huez or some shit. Frank Shorter drank de-carbonated Cokes when he raced. Same thing.

And when marathoning became the everyman’s Everest, it was determined that it was necessary to refuel often so that you didn’t have a whole Rock and Roll marathon full of zombies, all sideways and drooling, lurching toward the finish line. And all the training programs bought it and so coaches began to instruct everyone to take heed and start sucking gels or chomping bloks every 45 minutes or whatever. On training runs. And so that evolved—or devolved, if you’re old school—into a bunch of people taking gels at mile 3 of a 10 mile run. (Working on the floor one Friday afternoon, a guy came in and bough six gels of various syrupy sweet flavors. I asked him if he was stocking up for the next couple of weeks. No, he said, rather boastfully. Got a long run tomorrow. Fourteener. As if he was climbing a peak and not running to Crestview and back. I know, right?)

So here it is: If you are running less than two, two and a half hours you are not supposed to supplement with carbohydrate. Blasphemy, I know. But, but….No. You’re aren’t supposed to. One of the primary goals of a long run is to make you more efficient in fuel expenditure. And so if you are supplementing along the way, you are not allowing your body to do what it is supposed to do, you are not going to achieve the benefit that you set out to achieve. You aren’t. Each workout has a purpose.

Yes, there are times when you should supplement carbohydrate in training. But those times are few and far between. In our group, we have two longer tempo runs that can be viewed as a race simulation or race prep or whatever the kids are calling them these days. Then, we take carbohydrate not to help us to get further down the road on that day, but because we are going to supplement a bit on race day and we need to make sure we know when and how to do it, to make sure our stomachs are ok with it.

And these days, with modern training methods, even four hour or four hour plus marathoners should need no more than one gel along the way on race day. I know. But I’m dead serious. Your program should be such that you can train your body to go much, much further on very little carbohydrate. And in fact—get this—most of us aren’t moving fast enough to have to worry about it anyway. The marathon is a race against fuel depletion. There are two types of fuel in use—carbohydrates and fatty acids. We have a limited amount of carbohydrate, which we’ve already discussed. And then we have a nearly unlimited amount of fat in our bodies for use as fuel. And your body’s preferred fuel at your marathon race pace is mostly fat. So why not make use of that?

There are several ways to make your body more fuel efficient. There are several ways to train your body to burn fat at a greater rate. Those are for another rant. But for now, the easiest way to do that is to use carbohydrate supplements only sparingly. Don’t be afraid of bonking or running low on energy. You’re supposed to bonk. It’s how your body adapts. It’s how you become better. It’s how the big boys and girls do it, and how you should do it to.

Next time, when I can find a soap box and a steady stream of caffeine infused beverages, I’ll tell you a little bit about everything.