Despite all the medi-speak the diet books throw at you, just about everything you eat falls under the three categories that you already know: carbohydrates, proteins, or fats. Nutritionists have long advised us to eat 60 percent of our calories as carbs, 15 to 20 percent as protein, and the rest in fats. Carbs are converted to blood sugar, or glucose,
which gets stored primarily as glycogen, a kind of muscle fuel. Proteins are made up of individual amino acids that help build muscle tissue. The more muscle you have, the more protein you need to restore it. Fats help you build cells and maintain a stable body temperature.
Those of us who go long-and-strong in the outdoors need carbohydrates most of all; they should make up 60 to 70 percent of the fuel you need for aerobic activity. "Carbohydrates are the only source of energy that gets stored in the muscles," says Nancy Clark, a registered dietician at the SportsMedicine Center in Brookline, Massachusetts and the author
of Nancy Clark's Sports Nutrition Guidebook. "If you run out of glycogen, you hit a wall."
Still, it is true that many of us don't eat enough protein. While the U.S. Recommended Dietary Allowances instruct nonathletes to eat .36 grams of protein per pound of their ideal body weight per day, active people should get a half to a full gram of protein per pound, according to Herrin. This hefty intake partly helps revitalize sore muscles, and
partly restores what they burn for energy. "When we first learned how carbohydrate adds to endurance, it was very exciting," she says. "I think we may have swung too far to the extreme, and simply told everyone to go with low-fat, high carbohydrates. To simplify the message, nutritionists almost had a plot against protein for a while."
The scheme might help explain those athletes who noted performance gains from lower-carb diets. "The people who got good results were people who had pretty rotten diets to begin with," says Ellen Coleman, the author of Eating for Endurance. "I had one guy who was living on pasta and PowerBars and he couldn't understand why he was hungry all the time. I
had to introduce him to chicken and tuna."
So how much fish and fowl should we be taking in? The standard formula is all but baffling: First, determine your lean body mass. Then, calculate your protein needs in tenths of a gram per pound. Lastly, explain all this to your butcher.
For a more useful yardstick, Clark suggests you begin by figuring out where you're getting your protein. Then, forget the calorie charts and simply make sure it covers a third of your plate's surface area. This may constitute a cup of milk with your morning cereal, or two ounces of meat in your sandwich at lunch. From there, fill the other two-thirds of
your plate with grains, fruits, and vegetable-based carbs. As for fat, Herrin suggests you drizzle a tablespoon of olive oil on your greens.
As for portion size, the reasonably fit and healthy should follow this simple rule: Eat when you're hungry, stop when you're not. "Listen to your body and the tailoring will happen naturally," says Herrin.
This won't mean constant noshing, however. Herrin counsels athletes to eat often, but in an organized way—three meals and three snacks. "Use snacks to fill in what you may have missed in your other meals," she suggests. You'll also want to down a quick-burning form of carbohydrate, such as a sports drink, after you hang up your snowshoes, to
restore depleted glycogen.
When it comes to timing meals, Clark says, athletes often worry too much about the hazards of a full stomach and not enough about those of an empty one. Precede a morning workout with a digestible source of carbohydrates—say, a bowl of cereal with banana. While intense exercise may make your stomach feel as if you've swallowed your CamelBak, steady
aerobic activity such as a long, slow run will actually speed along your digestion slightly.
TRUST YOUR GUT
All of which spells something less than the diet revolution as seen on infomercials. Just as the bagel-and-pasta bonanza of years past was a little unreasonable, protein pundit Barry Sears' advice that "the stomach cannot tell the difference between a candy bar and a plate of pasta" also sounds askew. Even the U.S. Cross Country Ski Team tends to play it
by ear when it comes to eating right, according to team program director Luke Bodensteiner. "The key for these guys is to eat a lot of really healthy food. They try to mix in some protein in every meal but not a ton of it."
Lastly, when packing your nutritionally balanced fuel onto the trail, don't neglect to heed environmental factors. "During winter workouts, the ski team tends to rely on sports drinks," Bodensteiner says. "The bars all freeze up and can get pretty difficult to eat."
Paul Scott is a frequent contributor to Bodywork.
Photo: Craig Cameron Olsen