Wednesday, April 30, 2008

The first question I'll attempt to answer with this blog is whether or not a low-carb diet can work for serious endurance athletes. I know, all you know-it-alls out there are screaming, "hell no!" at your computers right now. I have a few reasons for believing that low-carb may be the way to go for endurance athletes eager to drop a few:

1. Endurance training is done at a relatively low intensity. Even if you feel you're going hard, you're likely nowhere near your maximum effort. At lower intensities, the human body will call on fat for energy and doesn't actually need carbohydrates. Most of my swimming and biking is done with my heart rate at 120-140 bpm, while running is done between 150-170 bpm. Now, I'm a little worried that my running performance will seriously suffer, because at 170 bpm I should get about 65% of my energy carbs and without many (if any) in my system, it'll likely be impossible to maintain my intensity. But I guess we'll find out!

2. Believe it or not, I feel it's harder for serious athletes to lose weight than the average Joe or Jane. When I'm taking a "rest" period at the end of a season, my appetite drops dramatically and I have no problem achieving a calorie deficit. However, when my training is ramped up to 2-4 hours per day, my stomach becomes a furnace and I end up eating upwards of 4,000 calories per day. Cutting out one out of the three major nutrients (carbs, fat, protein) will inevitably make your daily caloric intake plummet.

3. While high-quality carbs (whole grains, beans, etc) have a negligible effect on blood sugar, most carbs tend to mess with it -- especially sugar and "white" starches. Maintaining steady blood sugar levels has been proven to steady one's metabolism, which can trim an extra 300-500 calories per day.

So today marks day one of my carb neglect. I weighed in this morning at 168 lbs., about three pounds heavier than I was at Ironman Florida last season (my lowest race weight of the year). So far I've survived the day on five egg whites, one whole egg, an EAS Advantage Carb Control Bar (2 grams of net carbs) and lunch consisted of a chicken skewer and cabbage salad. I managed a 25-mile, low intensity ride this morning and I'll get in another 18-mile ride this evening. I'll let you know how it goes.

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