Myths About Weight Loss And Exercise Performance

MYTHS ABOUT WEIGHT LOSS AND EXERCISE PERFORMANCE

(Bethesda, Maryland) — “With the continuous onslaught of new diets and advertisements for supplements to lose weight and build muscle, it’s no wonder people get confused. The best way to make sense of these weight loss promises and exercise performance claims is to arm yourself with the facts,” says Susan Kalish, executive director of The American Medical Athletic Association, a nonprofit organization of sports medicine professionals who come together to disseminate information on the benefits of exercise and leading a healthy lifestyle.

Myth: Cutting carbohydrates from your diet is an effective way to lose weight.
“Most individuals on the high-protein, low-carbohydrate diet believe they lose weight by eliminating carbohydrates. In truth, they lose weight simply because they have reduced the amount of calories they take in,” says Nancy Clark, M.S., R.D., author of Nancy Clark's Sports Nutrition Guidebook, Second Edition. “Initially, the weight change is caused by a rapid loss of water, not fat,” adds Karen Reznik Dolins, M.Ed., R.D., nutrition consultant to the New York Knicks. “And after a short period of time, muscle is lost in addition to fat.” With less muscle, the body burns fewer calories, making this diet a poor choice for long-term weight maintenance. “Don’t be fooled by anyone who tries to convince you that fruits, vegetables, and whole grains will make you fat,” warns Reznik Dolins. “These foods are an essential part of a healthy diet and, as the primary fuel source for muscles, they are crucial to an athlete’s diet.” Without adequate carbohydrate intake, the active person will undoubtedly experience drops in energy levels and exercise performance.

Myth: The fewer calories you eat, the more weight you lose.
This is true only to a point. “If you restrict your calories too much for an extended period of time, you can actually trigger what is known as the ‘starvation adaptation response.’ This simply means that your metabolism slows down to accommodate your lower caloric intake, and your body conserves fat rather than burning it for energy,” explains Susan M. Kleiner, Ph.D., R.D., author of High Performance Nutrition. Even a person who works out regularly can hold onto body fat and end up at a weight-loss plateau if not enough calories are being consumed. “Low-calorie diets are also a disaster for anyone wanting to maintain or build muscle. Such diets cause your body to store fat, as well as burn healthy muscle,” warns Kleiner. “Never go below 1,200 calories per day if you’re a woman and 1,600 if you’re a man.”

Myth: To build muscle, you need to supplement your diet with extra protein.
“There is no research showing that taking in extra protein enhances muscle weight gain,” says Melvin Williams, Ph.D., author of The Ergogenics Edge. Active individuals need about 12% to 15% of their total daily calories to come from protein. Some may need more than the Recommended Dietary Allowance (RDA) of 0.8 grams protein per kilogram of body weight, but even they should not exceed a level of two to 2.5 times over the RDA. “For an endurance athlete, the upper level of the recommended amount is 1.4 grams per kilogram body weight; for a strength-trained athlete, the upper level is 1.8 grams per kilogram of body weight,” says Williams. Excess protein in your diet can cause dehydration, kidney and liver problems, and, according to a study by the National Cancer Institute, it has been linked to kidney cancer.

Myth: The less body fat you have, the better.
Female athletes who lose too much body fat can be at risk for a condition referred to as The Female Athlete Triad. This is characterized by inadequate nutrition, loss of menstruation, and early-onset osteoporosis, which is often irreversible. In women, fat is needed to support child-bearing functions and essential fat (11% to 13% for women and 3% to 5% for men) provides calories for energy, protects internal organs, makes hormones, and keeps you warm. “For optimal health, no one should drop below their level of essential fat, nor should they exceed ranges that would put them at risk for heart disease, diabetes, high blood pressure, and stroke,” advises Kalish. According to Clark, women should not exceed 27% body fat and men, 17%.

Myth: Sweating is a great way to lose weight.
“Sweating is the way your body cools itself, and weight loss during exercise often represents a loss of fluids from the body—not a reduction of fat,” says Kalish. “Rather than rejoicing about the number of pounds you’ve lost, you should calculate the amount of fluids you need to replace. For every pound you lose following a bout of exercise, you should drink at least 24 ounces of fluid.” Progressive dehydration occurs if you do not fully rehydrate after each workout, and this can have a negative effect on your health and exercise performance.

For more information on how to eat smart to fuel your active lifestyle, send a self-addressed stamped envelope (55¢) to Nutrition for Performance, The American Medical Athletic Association, 4405 East West Highway, Suite 405, Bethesda, MD 20814. For a variety of articles on nutrition and exercise-related topics, visit http://www.americanrunning.org/.

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