Monday, August 17, 2009

The merits of not eating!

I am a big believer in eating a big breakfast before a big bike-ride, and then refueling with sport drink during the ride, and eating a recovery meal afterward. Here's a typical quote of Monique Ryan supporting that view:
"As all cyclists know, muscle glycogen is an important fuel source during most any ride, whether easy or more intense and depending on your training intensity, muscle glycogen can become significantly depleted in 75 to 90 minutes."
She recommends as much as "3 g of carbohydrate per kilogram of body weight (1.4 g per pound), or 225 g for a 165 lb. cyclist." I've tried to eat that much; it's not fun! I now believe that it isn't always necessary to eat that much, depending on various things. Sometimes eating less can help us become faster cyclists, believe it or not.

What changed my mind on this issue was a few things:
  • I remember my early days of big rides when I'd ride for 3 to 5 hours with no food. Or maybe just one energy bar at most. I didn't know any better but never bonked that I recall.
  • I read several articles in which sport nutritionists and athletes discussed eating less as a way of enhancing fat-burning capability. That in turn spares the more-powerful muscle energy source, glycogen, which thus allows them to be faster in long races.
The basic concept is that constantly eating food during rides makes your metabolism 'lazy' and more inclined to just grab the glycogen, saving the fat for later. This prevents you from burning body fat, and makes you more vulnerable to bonking on long rides if you forget to eat enough. Denying your body a constant source of glycogen forces it to adapt to burning more body fat instead. Makes sense, but is it true?

I recently did a test of this theory: With 891 calories for breakfast I did a workout ride with teammates for 5 hours including 75 minutes of race-speed climbing up Bonny Doon Road on just plain old water. I kept my power in the correct training zone ("L4") and burned 2,464 calories. Not bad! That means the other 1,573 calories came from my energy reserves. Some undoubtedly came from my dinner the night before, but if "when you wake up in the morning, your liver glycogen stores are only about one-fourth to one-third full, at about 80 grams worth of carbohydrate" is true, then obviously a very large portion must have come from my fat stores.

So, am I lean too? Yeah, I think 6% body-fat qualifies. But I'm more concerned that I can save my glycogen for finish-line sprints, and that also seems to be working better now.

Here are some articles for reference:
So, this training method may make sense some of the time, but I would definitely not use it all the time. I don't know how often this can be done, but for now I'm saving this for some of my Saturday "L4" workout rides (with an energy bar in my pocket just in case!). In the off-season I may try it more often, but I will still eat during long road races and my "L5" workouts.

Ciao, not "chow," for now!

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