"There's only one hard and fast rule in running: sometimes you have to run one hard and fast."

Tuesday, January 20, 2015

Have you tried the standard model?

When writing about any subject long enough, you start writing about weird stuff just to have something new to say. This is post #1157 about running here, and I haven't resorted to reviewing shoes or showing pictures of vacations [cough cough, like every other blog], but I have veered off course a bit.

There's a weird fascination with food among runners and the latest craze is eating low-carb (defined as anything less than what one ate last week). The way these things work is that a successful runner gets interviewed and there's nothing new for them to say [I trained really hard and was a little lucky], but they mention something about their diet and voila! there's something to write about. Then another says the same thing and it's a trend.

Runner A runs 140 miles per week and eats a low carb diet. Runner B runs 130 miles per week and eats a low carb diet. Average Runner hears about this and says, "Well, I can't run that much, but I can change what I eat. That's the way to be a better runner!"

The breakdown

If you run 10 miles fourteen times per week, your muscles are always being depleted of glycogen and you burn a greater per centage of fat to sugar because of it. If you're doing that and eating a high carb diet, your body also becomes better at storing sugar at the same time. If you're eating a low carb diet, your body doesn't have any sugar to store, so you burn a slightly greater amount of fat than you do on a high carb diet - the difference is generally small.

Now, if you're only running 10 miles three times per week and you switch from eating 60% carbs to 40% carbs, it does absolutely nothing physiologically. If you dropped to eating 5-10% carbs, your body will indeed burn a slightly higher ratio of fat to sugar than it did before, but it will mean absolutely nothing to your racing ability.

Run more.

What you eat might account for the last 5% of improvement and what shoes you wear might be the last 0.5%, but training accounts for the rest of it.

Go out and f#$%& run!

I'm really talented at squeezing out the last couple per centage points out of runners, getting someone whose run a half dozen marathons in 3:05-3:10 to finally break the 3:00 barrier, but that's really just the frosting on the cake. You have to do all the work necessary to get to 3:10 to begin with. What you eat won't get you from 4:00 to 3:10.

Stop reading this and do your workouts!!!!


Alicia Hudelson said...


Carilyn said...

Okay, I love this post. I hope you will post it to Twitter (if you haven't already). Almost without exception, every runner I know who went low carb for an extended period of time a) lost some weight; b) got a little faster; and c) ended up with some sort of endocrine problem.

Now, "a" can be attributable to ANY restriction diet - cut something out and you will generally lose weight. It follows that, if you lose weight, you will probably run faster. And finally, many of those great runners have never recovered fully from the endocrine problems.

I had started to look into the "Paleo for runners" fad right about the time Pam Smith and Timothy Olsen won WS100. She followed a high carb diet (and as a doctor, she detailed the reasoning for it on her blog) and Timothy followed a low carb diet. They both won.

Robyn said...

Pam Smith's diet was NOT high carb. She was aiming for 100 g carbs/day before easy training days, and 200 g before long runs. That's not ultra-low, but it is lower than the Standard American Diet. Here's what she said about it in her iRunFar article after winning WS100:

"Looking to get the metabolic benefits of Paleo, but without the extreme restriction, I found another method of eating ... called “Carb Back Loading.” ... The general idea is that you only eat carbs at times when the body is most likely to utilize them for muscle repair and glycogen storage and not use it for fat. Essentially, this boils down to immediately after a workout and at night, when growth-hormone levels spike. My breakfast and lunch look very Paleo (eggs, meat, veggies, avocados), but my post workout recovery drink and my dinner are very un-Paleo and very high carb (rice, potatoes, polenta, quinoa). ... By eating carbs at night, I was always well-fueled for my morning runs, but then I spent the rest of the day in a more carb-depleted state. ...I do have carb guidelines (100 grams on nights preceding easy runs and 200 g on nights preceding hard workouts), but I am not anal about measuring my food and I do NOT count calories.
... I will tell you without a doubt in my mind, changing my diet made a difference. Whether this difference is actually due to a low-carb intake and nutrient timing or just some coincidental factor like decreased calories, increased protein, or increased food quality (less processed food, more veggies), I can’t say. But my crew could tell a difference, too. In 2010, they joked (very lovingly) that I was the “fattest girl in the top 10 at Western States.” This year my crew said, “Holy $hit! You’re ripped.”"