How much carb do we really need?
If you asked 100 runners, you’d probably get 100 different answers.
Not only are nutritional requirements highly individual, sometimes they’re wildly different.
My roommate in the early 1970s, Ian Jackson, once ran 140 miles in a week without taking any food at all – he was on a water fast. Ian had trained at a high level for many years – he’d been a college-level competitive swimmer – and he had an incredibly robust metabolism. Oh, and he ran most of those miles at sub-6:30 pace on tough hills.
If you read the standard literature, you’ll find that carbs are important for performance and recovery. Carbs are so important that researchers and high-performing elite runners sometimes talk as if recovery is mainly a matter of eating carbs until our leg-muscle fibers cry “Enough!”
For years, I believed that I could manage carbs better than most. I had two goals: to keep my weight under control, and to run with enjoyment. I thought the best approach was to restrict carbs on non-running days and “carb-up” on training days.
Now I’m not so sure.
The doubts crept in starting two weeks ago, when I began doing strenuous physical labor in a community garden, in addition to my usual running and gym schedule.
At 68, I wondered if I could do both without running out of gas.
As I generally do when I face a problem that defies rational analysis, I asked inwardly for guidance. “If you want me to do this demanding physical work, I need to know how I can have enough energy.”
The thought occurred that maybe I should be eating more carbs – a lot more. I went to Whole Foods and bought a bag of granola. (I like pumpkin seed flax.)
What was my surprise when I found I could work hard and still keep up my usual running schedule.
It was a radical change from my former understanding of energy. On my previous low-carb diet, I needed to take it easy on recovery days – I had enough energy to work at the computer all day, but little extra for physical tasks.
Last Thursday was a tough day. I cleared gutters for an hour, then finished digging a hole for a fig tree. The hole needed to be 3 feet wide and 3 feet deep to accommodate a gopher-blocking wire mesh to protect the roots.
Later, I ran 35 minutes in the hills behind Stanford and threw in several 10-second bursts. I then went to the gym and did bench presses, ab work, and deadlifts. I was surprised to find that my energy remained high throughout.
Clearly, I had added a chapter to my personal understanding of fueling the running body. The sequel is that, just three days later, I was able to run 2 hours, mostly at 80% of MHR or faster, feeling fine all the way.
I shouldn’t have been surprised. In an earlier article, Carbenflarb: Fact and Fiction About Fats and Carbs, I wrote:
The hard-training Kenyans eat a carb-rich diet. From Run to Win: The Training Secrets of the Kenyan Runners, by Jürg Wirz:
According to the ICEARS [International Center for East African Running Studies] study, the daily carbohydrate intake of elite distance runners in the United States and the Netherlands has been measured at 49 and 50 percent of total calories, a far cry from the Kenyan total of 76.5 percent. The Kenyans appear to do a far better job in fueling themselves for their very demanding training.
Arthur Lydiard’s elite athletes, including Peter Snell and Murray Halberg, ran a hilly 22 miles on Sundays without taking extra fuel. But, before and after their runs, they gorged on carbs.
Keith Livingstone, a former elite runner from New Zealand and author of the excellent Healthy Intelligent Training: The Proven Principles of Arthur Lydiard, describes how he would eat piles of toast and honey after his long runs. He also tells how, when Lydiard’s original runners began visiting an all-you-can-eat Chinese buffet after the weekly 22-miler, they ate so much that the owner finally had to beg them, with tears in his eyes, not to come in on Sundays because he couldn’t make any money serving them.
In the weeks since I started eating more complex carbs, my legs have felt stronger on long runs, I’ve been able to run fast with less strain, and I’ve recovered much more quickly. I’ve also had more energy for work.
I do believe I’ll have a little more pilaf.
Yes! Of course you need carbs. They are your fuel! Running your body on fat and protein is like running your car on cooking oil – it might work work but neither you nor your car will be very happy about it.
This is true in my own experience. I used to undereat carbs, guesstimating my carb intake was around 40-50% of daily calories. My legs were constantly tired. After realizing what I’ve been doing, and switching to an all fruits and vegetables raw vegan diet, at 80+% of daily calories from carbs, this problem is just totally gone.
Now you don’t have to go all in with the only fruits- and veggies diet, but high-carb is in my experience the one way to go. Check out the book the 80/10/10 diet by Douglas Grahams if you’re interested. It offers an interesting alternative to most of todays’ “normal” ways of eating, promoting a diet consisting primarily of fresh fruits and vegetables. And there are runners getting fantastic results on this diet, check out http://www.thefruitarian.com/ for example.
David – Thanks for the interesting comment. I will check that book. By the way, you say your diet consists of fruit and vegetables. I have to assume you’re eating grains as well? Potatoes? Reason I ask is, when I tried getting carbs only from fruit (oranges, etc.), I quickly ran out of gas. (I was avoiding dried fruit – raisins, dates, etc.) But when I started including rice, wheat, and potatoes, my energy perked right up.
In any case, thanks for the heads-up to Douglas Graham’s book. My legs sure feel stronger and more enduring than when I was limiting carbs a bit too much. I now realize that one reason heavy trainers are able to keep up big mileage is that they take care to stoke up. That said, however, I recall Bernd Heinrich’s observation, in his interesting book, Why We Run, that as he amped-up his mileage from very little to 100+ mpw in preparation for an attempt on the US 100K record, he found that he didn’t have to eat very much more. He theorized it was because his body grew more efficient in drawing calories from food (and presumably from stored fat). Of course, Bernd did take cranberry juice as fuel during training, and it contained sugar.
Anyway, carbs are an interesting “experiment of one” for us all. Thanks again!
You’re welcome 🙂
No, I’m actually only eating what I said I did – raw fruits and vegetables. I do eat some nuts and seeds, but no grains or other starch-based carbs like potatoes or rice. And yes, it is possible to get enough calories from fruit alone, it just takes a bit getting used to the quantities – a meal for me might be 10-15 oranges or 10 bananas.
This diet is somewhat of an experiment for me and I’ve only been doing it for a couple of months. But so far, I’ve got more energy than before and I intend to continue until that changes.
Haven’t heard of that book, Why We Run, sounds interesting.
Hi again, David – What can I say but “Way to go!” Hurray for anything that gives us more energy, eh?