• Choose a category
• All
• Classic-Fiction

This apparent contradiction is similar to discussions of the “fat-burning zone” for weight loss (see Chapter 9). In both cases, researchers have figured out how to make the body rely more on fat instead of carbohydrate—but you don’t lose more weight or bike faster, because the body seems to compensate for the change. In fact, there’s some evidence that in increasing your fat-burning abilities, you also harm your carbohydrate-burning capacity. It’s tempting to believe that this doesn’t matter in ultra-endurance events like marathons or 100-mile bike races, where fat-burning plays a major role. “However,” Australian Institute of Sport nutritionist Louise Burke pointed out in a 2007 commentary, “the strategic activities that occur in such sports—the breakaway, the surge during an uphill stage, or the sprint to the finish line—are all dependent on an athlete’s ability to work at high intensities that are carbohydrate-dependent.”

In practice, there are two approaches to training in a carbohydrate-depleted state. One is the approach used in the studies described above: deplete your muscle glycogen stores with 30 to 60 minutes of moderate exercise at about 70 percent of maximum effort. Then, without refueling, do some harder training. Alternatively, you can try working out first thing in the morning without eating anything first, possibly having eaten a low-carbohydrate dinner the night before, so that your whole body is low on glycogen. Both these strategies can be very stressful for the body and shouldn’t be attempted more than once or twice a week. Recovery afterwards is crucial, including lots of carbohydrates.

At this stage, although “train low, compete high” has become a popular buzz-phrase, the research remains highly uncertain. For most people, the best bet is to let others do the risky and often unpleasant experimentation—then, if it does turn out to provide measurable performance benefits, give it a try once the details have been worked out.

Can I get the nutrients I need for a heavy exercise regimen from a vegetarian or vegan diet?

Running 167.7 miles in a single day, as 36-year-old Scott Jurek did in setting a new American record for the 24-hour run in 2010, is a staggering feat by any definition. But Jurek’s accomplishment garnered extra attention because he follows a strict vegan diet. How was it possible, people wondered, to run over 140 miles week after week and consume 5,000 to 8,000 calories a day, with no meat or animal products?

For decades, would-be vegetarian athletes have been warned about the shortcomings in their diets, like the possible shortage of essential elements such as protein, iron, and calories. But only a few isolated studies have compared the actual performance of vegetarian and omnivorous athletes, with generally favorable results. One in 1970 found no difference in lung function and thigh muscle size between the two groups. A 1986 Israeli study found no difference in serum protein between vegetarian female athletes and matched controls, and a 1989 German study found no difference between vegetarians and non-vegetarians in the finishing time of a 1,000-kilometer run.

HIGH-PROTEIN PLANTS

Spinach (3 cups, cooked): 15 g of protein

Asparagus (3 cups, cooked): 12 g

Lentils (1 cup, cooked): 18 g

Oats (½ cup, dry): 13 g

Quinoa (1 cup, cooked): 8 g

It is, of course, entirely possible to consume an unhealthy and deficient vegetarian diet. If you took a typical North American diet and simply removed the meat from it, you’d almost certainly not get enough protein to support a heavy exercise regimen. But if you take the time to consume good sources of vegetable protein, you’ll have little trouble meeting your protein needs (see Chapter 5). Similarly, getting enough calories is simply a matter of eating more. “The first thing to worry about isn’t so much what you eat, but how much you eat,” Jurek explained to a New York Times reporter. “You have to take the time to sit at the table and make sure your calorie count is high enough.”

There