Monday, March 5, 2012

The Carbo-Loading Tradition?

As many of you may remember, I returned from Nepal just a few days before being whisked off to Miami for my first half marathon! Traveling with a large group of friends- all more experienced runners than me- the night before the race I was out voted on what we would do for dinner. Everyone seemed to agree, lentils were out. Italian was in.

We found a small, lovely Italian restaurant somewhere in Miami. Everyone was getting the same thing- pasta.  For those of you who have been with me since my first post know I’m skeptical about the benefits of having pasta in my diet. Actually, to be specific, I think processed wheat products are a detriment to athletes due to their low nutrient value. Anyway, out numbered and hungry I created a custom order. It was a huge bowl of whole-wheat pasta, cannellini beans, kidney beans, spinach, garlic and fresh, diced tomato sauce. In all honesty, it was both beautiful and delicious. 

Sorry I didn’t think to grab a picture of the actual dish!

The next day I awoke at 4 am for the race and I didn’t feel anymore fueled than usual. While I did fine during the race, and so did all of my companions, it got me thinking about how carbo-loading actually works and so here is my understanding of the science behind the tradition. 

The earliest research on carbo-loading dates back to the 60s when Scandinavian scientists studied non-athletic men’s ability to perform on low carbohydrate and high carbohydrate diets. They found that the low carbohydrate diet resulted in lower muscle glycogen stores which negatively impacted their endurance. When the same men consumed a high carbohydrate diet for several days, their muscles became supersaturated, and endurance times were significantly extended. Based off these studies they created a 7-day program. This program has since been replaced and updated although the general idea has remained the 

Other studies have shown more effective approaches. Tapering your workout regimen while simultaneously boosting your carbohydrate intake can allow you to supersaturate your muscles in as little as three days. When used correctly, this method can amplify your endurance by nearly 20%. In practice, this can help you increase your distance without “hitting the wall” as well as your time. Some studies suggest that your time can improve by as much as 2 or 3%. While it sounds like a small increase, in a multi-hour event that will add up to several minutes!

   Okay, so how and when should you carbo-load? Carbo-loading only works for endurance events. Most authorities agree that the performance needs to last at least 90 minutes before carbo-loading will begin to help improve your performance, so unless you are crawling, you probably won’t need to eat a large bowl of pasta every night for a week before your big 5K that you are training for. Instead just try consuming healthy, high-net value foods. These studies even suggest that the most elite marathon runners, those freaks, mutants, people who run 26.2 miles around the two hour mark also don’t greatly benefit from carbo-loading. This is because it typically takes around 90 minutes of sustained exercise before glycogen levels begin to run low. (More elite athletes will be able to train their bodies to sustain themselves off their fat storages during these endurance events rather than depending on carbohydrates.) If however you are running a marathon and you’re not a super human, carbo-loading is a great idea. 

But before you go running off to your local organic grocer to buy them out of whole-wheat pasta finish reading. Gender also plays a role in how beneficial carbo-loading will be. As evidenced from above, the earliest studies were all conducted on men-and those sexists scientists simply believed that women would experience the same results with muscle supersaturation. However, more recently, studies which focused specifically on women found that females have a more difficult time reaching a supersaturate point than men. Another study was unable to demonstrate any measurable benefit to the women’s performance after reaching supersaturation. Part of the reason has to do with the menstruation cycle. Women have an easier time carbo-loading during and immediately after menstruating. Another factor is that women typically have smaller caloric needs than men and simply can't increase their carbohydrate intake enough to gain benefits from it. As such, women may need to dramatically increase their calorie intake for several days prior to an endurance event, paying particular attention to carbohydrates.

Finally, no matter how much pasta you eat the night before a race, no matter how much you gorge, chances are you will not be able to carbo-load that night. To reach a point where performance will actually improve, one needs to eat roughly 4 g of carbohydrates per pound of body weight each day. In a person who weighs roughly 150lbs, that means nearly 2,000 calories in carbos alone! I don’t know about you, but that seems intense!
note: Rich Roll no longer rides Jamis bikes.

The final verdict, in my opinion, is that most non-professional athletes won’t be able to achieve supersaturation of glycogen and should instead focus on staying hydrated and eating a large healthy meal before and after the event. As a very close friend always tells me, “you should never try anything new on race day.” That seems like sound advice to me! Luckily for me, green lentils are 70% carbohydrate so I’ll be BYOL’ing for my next endurance event!

Brazier, B. Thrive (2007)
Burke, L. Middle- and long-distance running. (2007)
Burke, L. Preparation for competition. (2006)
Coleman, EJ. Carbohydrate and exercise. (2006) 

1 comment:

  1. This is a great article and very current with the modern science behind Carb-loading. The NYT recently did an article on carb-loading and found that, in fact, a balanced meal before and after an endurance sport has better benefits.
    Anyways, thanks for posting!!