Running Away from Carbs

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So, what’s the difference between burning a piece of paper and burning a candlestick?

I’m about to tell you something that, most likely, is completely contrary to everything you’ve ever been told about the ideal diet for runners. Ready? I hope you’re sitting down. (Of course you are! You just got back from a long, hard run.)

Carbohydrates are probably not the best thing to eat. In fact, runner or not, they might be downright bad for you. We’re told as runners that we need to eat lots of carbs, make sure you carb-load before races, blah, blah blah. It’s such conventional wisdom! A college classmate and good friend of mine is a marathoner that avoids carbs like the plague, and I never understood how she managed until very recently. This may seem like anecdotal evidence, but I’ll give you the science soon – I swear.

But before we get there, a little backstory: a few weeks ago, I went to the doctor’s concerned about the weight I’d gained in spite of my diet and exercise regimen. All of the normal things were checked: my thyroid was fine, I was negative for diabetes, but some odd stains on my neck led my doctor to conclude that I was probably insulin resistant, which would make it difficult to lose weight. Because of this, he suggested that I should give up carbohydrates entirely for a while and go on a low-carb, high-fat diet. If you remember the mid 2000’s, you remember the Atkins diet, which is pretty much exactly that. If you want to see why this works (and it does), I’ve found some infographics here and here.

So, I cut out carbs. I started eating a high-fat diet with lots of leafy greens, being careful to record everything I was eating. It was the first instance ever where fruit was pretty much out. What did meals look like?

– Eggs and bacon with some green peppers.
– Bacon and egg muffins.
– Chicken thighs (skins and all) with spinach salad.
–  Keto pizza with low-carb crust, plenty of cheese and pepperoni.

Now, how does my neck and a trend diet from eight years ago relate to you, as a runner? The reasoning behind going on a ketogenic diet (or a paleo diet, even) is awfully similar to the changing attitudes about wearing cushioned, traditional running shoes. Cavemen that chased their prey down for miles and miles didn’t wear high-tech padded shoes, and we’ve come to the realization that we don’t need to, either. You know what cavemen also didn’t do? Eat pasta before a run.

For long runs, you stuff yourself with sugar or carbohydrates – via pasta, Powerade, Clif bars, gels, whatever. But if you’re a runner worth your salt, you know that feeling of “hitting the wall”, and how you pretty much feel like you can’t even move anymore, let alone continue running. Hitting the wall is caused by your body exhausting its glycogen stores. (Here’s the hard science, if you desire.) But, you know that if you can push past hitting the wall, you suddenly have more energy. Now, the body isn’t stupid. It gets its energy by using whatever it has the most of. Runners hit the wall because they’re out of glucose, and you feel better when your body “changes gears” to burning fat. On a ketogenic diet, you’re always burning fat as your body’s primary energy source, and it’s no longer like “a light switch”, but more like the transmission of a car.

Back to my question regarding the piece of paper and the candlestick: the answer, of course, is that one burns up very quickly (the paper, duh), and the candlestick takes forever to burn. Carbohydrates have an enormous amount of energy, like paper, but it burns very quickly – carbs are broken down immediately for energy, whereas fat sticks around longer, burns up slower, and is used once all of your glycogen gets used. Fats, which are the primary source of your body’s energy on a ketogenic diets, are composed of long chains of hydrocarbons, take a long time to burn off, and are much more sustainable as a long-term source of energy, just like a candlestick is a more sustainable source of light (and heat) than a burning piece of paper.

This might all sound crazy to you, and I understand that – it did to me a while back when a friend of mine decided to forgo carbs, and even crazier when a friend of mine in college gave up anything and everything containing corn in all forms, but both had pretty amazing results. In the two weeks since I started, I’ve lost about eight pounds, the evidence of my insulin resistance (the stains on my neck and arms) have been going away, and other benefits are starting to come forth (sleeping better, more energy during the day, etc.) I have not put it to the test on a run, yet, mostly because I wanted to make sure my body was well-adjusted before I tried any strenuous exercise, but there’s a few 5ks coming up.

I’ll post another update later on as I get runs in and let you know how this diet works for runners. If anyone else out there has tried out a low-carb or Keto diet, let us know how it worked for you in the comments!

Candle image from