Hiking 30 miles and running 30 miles are incredibly different endeavors.
I’m used to very long distance hikes, and in those cases I carry food and eat along the way. When running, though, I adopted the philosophy over the winter that if I’m going out for less than 20 miles I don’t need to carry food or water. When it’s cold I lose less water and it’s available to me periodically in the form of snow and snowmelt [yeah yeah, it’s dangerous to drink wild water, I don’t care]. In the case of a big ascent, I might bring a little snack but I definitely haven’t spent much time considering my “refueling plans”..until now.
I suppose it’s about right that I set 20 miles as the magic number, because now that I’m regularly exceeding it I’ve noticed that something terrible happens right around 21. I’m feeling great, then suddenly I’m barely dragging myself along; in pain and miserable. I don’t hang out with other long distance runners, so I’m figuring it out as I go and during my first 30 mile run, I learned about THE WALL.
First, let’s talk about how our muscles get energy [WARNING: shit’s about to get science-y. If that sounds boring, skip the next 5 paragraphs]
Digestion breaks down energy containing nutrients and sends them to your cells via blood. Once they’re in your cells, the nutrients are either built up into proteins, lipids, and glycogen OR converted [to pyruvic acid or Acetyl CoA] for energy production. If you’re wondering why people say B vitamins are important for energy, it’s because they’re very important in conversions to Acetyl CoA. There’s more detail here that we just won’t go into.
So now we head to the mitochondria. There’s basically two ways your body creates energy (and by energy I mean ATP- the official energy currency of your body). Glycolysis is quick and dirty- it gets results fast but isn’t very efficient, and there’s a lactic acid problem. Kreb’s Cycle is the tortoise- slow and steady, and much more efficient. This stuff is cool because it explains exactly why lactic acid (what makes muscles stiff and sore) happens. Glycolysis is anaerobic, it can happen without oxygen (like during strenuous activity when you just can’t breathe enough in) BUT it creates extra hydrogen, and that hydrogen needs to be pawned off somewhere. If oxygen is available, hydrogen will go home with him (creating water-nbd) but otherwise hydrogen gets dumped on pyruvic acid, and that’s how we end up with sad little lactic acid, gumming up the works.
Basically, when you start running your body is going to use ATP it’s already made to make your muscles work. It’s constantly working to produce more, but you’ll use it faster than you can make it. Desperately, glycolysis will bust ass for you (most of us are at this point when we exercise). But what happens if you keep going? Incidentally, your body stores enough glycogen to keep producing ATP for 20 miles of running. (I fucking knew it)
Once you’ve used your ATP stores, your cells raid the glycogen stores to make more. But WHAT HAPPENS WHEN YOUR GLYCOGEN STORES ARE GONE!?
That’s when you “hit the wall”. Your liver will start converting fat and protein to use in the energy making process but it’s not terribly efficient and takes up energy. Now refueling makes a whole lot of sense: GET MORE GLUCOSE INTO YOUR BLOODSTREAM!
So I did a lot of research about refueling and I have to say, most of it sounds gross. Eating while you’re running sucks. Period. The big problem I guess is getting food down without puking it back up. Yuck. So you need things that are palatable and go down easily. You’ll also want a good mix of simple carbs that get into your bloodstream asap (in minutes) and complex carbs that break down slowly and release small amounts of glucose into your blood over a long time. You don’t want to refuel with protein or fat; those two are the professional ebay sellers at the post office-holding everybody else up.
Here’s a knowledge bomb for you: compared to the type of machines we can build, our body is EPICALLY efficient. Through these processes we capture a whopping 38% of the energy available from what we consume (and the rest is RELEASED AS HEAT-boom. Why do you get hot when you work out? That’s why. You’re welcome.)
There’s a psychological aspect to hitting the wall for sure. I read somewhere that your discomfort when you’re dehydrated or under-fueled has a bigger effect on your performance than the physiological problems themselves. I’ll say firsthand that hitting the wall HURTS EVERYWHERE. I’ve noticed that I’m basically never sore anymore, muscle-wise, but when I’m on really long runs everything starts to ache. I get dizzy and woozy. My legs don’t feel like jelly, it’s more that I become the tin man. Yeah, it’s so uncomfortable it’s hard to continue. To cope, I’ve started counting. At first I count up to high numbers, and the deal is that when I get to 780 or something I can stop, but when I get to 780 I tell myself okay, now you just have to get to 780 again. Then when it gets really, REALLY bad I’m counting to 20. Interestingly, the promise of a fuel down is not an incentive anymore when I’ve made it past the wall; the idea of eating anything is gross and horrible and the only thing I can stomach the idea of is bananas or plain romaine lettuce.
Yeah, I know this post sounds terrible to those of you who haven’t experienced it. It’s so very hard to explain why we do what we do, especially when there’s a fair amount of suffering. I like to think of my training program as RELENTLESS. But that doesn’t mean I don’t love doing it. That first 30 mile run that I mentioned earlier; yeah it was painful and terrible and taught me lessons I’ll never forget. It was also when I realized that I can do Nolan’s. As far as I can tell, there are two barriers to cross: long distance and elevation gain. But you only need to cross them each once, after that you’re just building. Long distance mountain running is the highest of epic, joyous highs. And it’s the lowest of soul crushing, wish-you-were-dead lows. I can’t think of a better way to spend my time.