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Food To Fight The Bonk Factor

Choose your fuel wisely to keep your engine running strong.

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You’re tired, dog tired, and way past dragging along-you’re almost crawling. Every step is an act of will, and your usually pleasant demeanor was dumped

at that last switchback. Long-

distance runners and bikers have a name for this run-down feeling: “the bonk,” also known as “hitting the wall.” Right now, you’re considering hitting your partner, the one who suggested passing up the perfectly good campsite you just reached and hiking another mile in search of a better view.

You may not have thought of yourself as having much in common with runners and bikers, but you, too, are an athlete. Carrying a weighty pack up and down hills all day burns just as much energy as any other endurance activity. That’s why to perform your best and feel good doing it, you must eat like an athlete.

Here’s how it works. Your body converts everything you eat into three main energy sources: protein, fats, and carbohydrates. Of these, carbohydrates are the fuel of choice, since they’re more easily used by your body than are fats or protein. In fact, your body breaks down carbohydrates almost instantly into a simple sugar called glucose, which supplies energy to your muscles, organs, and nervous system. Excess glucose in the blood is converted into glycogen, which is stored in your muscles and liver and is converted back into blood glucose when your body needs extra energy.

“Your goal is to prevent fatigue,” says sports dietitian Nancy Clark, author of Nancy Clark’s Sports Nutrition Guidebook (Human Kinetics, 800-747-4457) and an advisor to athletes of all stripes, “and you do that by consuming adequate calories, carbohydrates, and fluid.” The bottom line here, reinforced by a mountain of sports nutrition research, is that anyone who wants to get the most from their muscles should have a diet that’s 60 to 65 percent of the all-important carbohydrates, with 15 percent protein and 20 to 25 percent fat.

If ratios and equations give you a headache, just listen to your body: It will tell you what it needs. “Active people tend to crave more carbohydrates because that’s what their body wants,” says Clark. Build all your meals around foods high in complex carbos, like vegetables, fruits and juices, beans, pasta, rice, baked potatoes, and whole-grain cereals and breads. Add reasonable portions of low-fat dairy products (skim milk, low-fat yogurt), soy products, and/or fish and lean meat (a serving should be about the size of a deck of cards), and you’ll have a healthy, bonkproof diet.


After establishing a good daily eating routine at home, you’ll need to fine-tune it for the trail, when your body is working hard and using up its reserves. “Your brain relies on sugar-blood glucose-to function,” explains Clark. “And of course, your brain controls your muscles and your ability to concentrate and basically just to function. Your muscles could still be well-fueled with glycogen, but if your brain isn’t getting the glucose it needs, everything will shut down.”

In real-life terms, let’s say you pound down a big pasta dinner at night, get up the next morning, skip breakfast, and go charging up the mountain. “You could have low blood sugar before your muscles have become depleted,” warns Clark. And that could mean symptoms ranging from fatigue, faintness, weakness, hunger, headache, confusion, personality changes, even loss of balance. In other words, you bonk.

The easiest way to avoid glucose lows is to supplement breakfast, lunch, and dinner with snacks throughout the day. For example, if you start your hike after a breakfast high in complex carbohydrates, you’ll have about 60 to

90 minutes of readily available energy. Exhaust that energy stockpile, and you’ll be playing a losing game of catch-up all day long.

To keep your glucose and energy levels at a good, even level, munch on dried fruit, gorp, fig bars, sports bars, or cereals like Cheerios or Chex every half hour starting about an hour after you head up the trail. Wash it all down with plenty of water or a sports drink, which is another good source of carbohydrates. Avoid any foods high in fat and simple sugars like candy bars. They’ll give you a quick fix, but little in the way of important vitamins and minerals. What’s more, injecting all that sugar into your system can send you crashing into the wall even sooner.

Here’s where the fine-tuning comes in: Nutritionists agree that the best window for replenishing your muscle glycogen is 30 minutes to 2 hours after you stop for the day, which is why it’s a good idea to eat something like a bagel and drink 12 to 20 ounces of carbohydrate drink once you get to camp. Keep in mind that nearly all sports nutrition research, even that focused on endurance events like ultramarathons and triathlons, is geared toward exertion that lasts for hours, not days. What’s more, none of these folks have to carry everything they need to eat.

So when it comes to lugging a big pack over hill and dale for days at a time, you might want to tweak your calorie ratio to allow a bit more fat and protein. Still, experts warn against doing anything drastic. “You have a choice,” says Clark. “You can eat raisins and apricots and sugary foods that are quickly digested, and eat them constantly. Or you can have a bagel with peanut butter, which will digest a little more slowly and last longer because of the high fat content.”

If all this seems like a lot of trouble, think about the last time you missed a gorgeous sunset because you were collapsed in the tent. Make complex carbos part of your routine at home, and keep energy as well as convenience in mind for all your backpacking trips. Next time, you’ll be leaping over the wall instead of crashing into it.

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