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Top Sport Nutrition Myths PDF  | Print |  E-mail
Written by Debra Wein, MS, RD, LDN, CSSD, NSCA-CPT, D   

Nutrition Myths

This article has been re-printed with permission from the NSCA’s Performance Training Journal, www.nsca-lift.org, Vol. 8, Issue 4

The field of sports nutrition is filled with myths that people follow blindly. This article looks at the top sports nutrition myths, and what science has to say about them.

Myth: The more protein I eat, the better.

Truth: While protein is necessary to support increased protein oxidation during endurance training as well as muscle growth for athletes participating in strength training activities, there is insufficient evidence to support the notion that “the more I exercise, the more protein I need.” Athletes should consume between 1.2-1.8 grams per kg of body weight or 10-35% of total calories (4,7,8).

Myth: It is not possible to drink too much water.

Truth: Headache, vomiting, swollen hands and feet, confusion edema, respiratory arrest and even death can occur in athletes who drink too much water. (7) Hyponatremia, low sodium in the blood stream, is more likely to occur in smaller, less lean individuals who run slowly, sweat less, and drink water (as opposed to fluids with electrolytes) before, during, and after exercise. (7) Weigh yourself before and after a “typical” exercise session to make sure you have not put on weight (which is a sign that you’re drinking too much).

Myth: An eight-ounce serving is the right amount of fluid to drink.

Truth: There is a large range in sweat rates and total sweat losses of individuals between and within activities making individual recommendations difficult (7). Individuals should strive to consume between 72 ounces and 100 ounces for men, and let their thirst be their guide according to the Institute of Medicine’s recent report on Dietary Reference Intake (5).

Myth: All athletes need supplements.

Truth: According to the joint ACSM/ADA position statement “…no vitamin and mineral supplements are required if an athlete is consuming adequate energy from a variety of foods to maintain body weight.” Athletes who are consuming too few calories (such as in dieting), is ill, recovering from injury or has a specific medical/nutritional reason to supplement, may benefit from a single supplement to correct that specific condition (6). Always remember, food first, supplement if needed. Speak to an MD or RD about your specific situation.

Myth: Vitamin C will prevent me from getting sick during my training season.

Truth: While vitamin C has been shown to lessen the symptoms and severity of a cold, research to date does not show that vitamin C supplements help individuals ward off colds (3). The best method to avoid getting sick is regular hand washing and a healthy diet. Vitamin C does play a role in respiratory defense mechanisms, so taking in additional vitamin C when you first feel a cold coming on may help.

Myth: Diluting sport drinks is a good idea to reduce my calorie intake.

Truth: Sport drinks are designed to provide a 6-8% carbohydrate solution and a reference amount of electrolytes to replace both fluids and electrolytes for athletes who lose these thru sweat. For exercises lasting 60 minutes or longer, taking in a sport drink, without dilution it is appropriate for optimal hydration (6).

Myth: If I’m thin, I don’t need to worry about what I eat.

Truth: Low energy intake compromises performance and negates the benefits of training. With a hypocaloric diet, fat and lean tissue will be used for fuel by the body leading loss of strength and endurance, as well as compromised immune, endocrine, and musculoskeletal function. A poor nutrient intake, may also result in metabolic dysfunctions associated with nutrient deficiencies as well as a lowered resting metabolic rate (RMR) (6).

Myth: I need to watch my weight because my BMI is too high.

Truth: Trained athletes typically have more skeletal muscle and less body fat than sedentary individuals. Therefore, BMI is not an appropriate disease risk screening tool for athletes (2). The Centers for Disease Control and Prevention (CDC) recommends that athletes use methods other than BMI to assess body composition. (1) Waist circumference is a good indicator of risk, as abdominal fat is a strong predictor of obesity related diseases (1). The CDC also recommends using Bioelectric Impedance (BIA), underwater weighing, or Dual-Energy X-Ray Absorptiometry (DXA) to determine body fat percentage (1).

Myth: Eliminating carbs will help me lose weight.

Truth: While taking in fewer calories than your body required (thru a decrease in any macronutrient-carbs, protein, or fats) will lead to weight loss, eliminating (or severely restricting) carbohydrates can lead to fatigue and poor performance as carbohydrates fuel your working muscles (even during high intensity activites such as strength training) (4,8). According to the Institute of Medicine, individuals should consume between 45-65% of total calories from carbohydrates (4,8), with athletes requiring the higher end of that recommendation (6).

The bottom line is do not believe everything you hear. Always consider the source and check to make sure your information comes from credible sources such as nationally recognized medical and research organizations.

References

  1. Centers for Disease Control and Prevetion. BMI for Adults. Retrieved July 21, 2008, from http://www.cdc.gov/nccdphp/dnps/bmi/adult_BMI/about_adult_BMI.htm, n.d.
  2. Dunford, M, and Doyle J. Nutrition for Sport and Exercise, Belmont, CA: Thomson Wadsworth. 2008.
  3. Hemila H, Chalker E, Treacy B, Douglas B. Vitamin C for preventing and treating the common cold. Cochrane Database of Systematic Reviews. 2007.
  4. Institute of Medicine. Dietary Reference Intakes for Energy, Carbohydrate, Fiber, Fat, Fatty Acids, Cholesterol, Protein, and Amino Acids (Macronutrients), Sodium, Chloride, Potassium and Sulfate, Washington, D.C: National Academy Press, 2005.
  5. Institute of Medicine. Dietary Reference intakes for Water, Sodium, Chloride, Potassium and Sulfate, Washington, D.C: National Academy Press, 2005.
  6. Rodreiguez N.R., Di Marco N.M., and Langley S. American Diebetic Association; Dietitians of Canada; American College of Sports Medicine of position stand. Nutrition and athletic performance. Med Sci Sports Exerc. Mar;41(3):709 – 31. 2009.
  7. Sawka MN, Burke LM, Eichmer ER, Maughan RJ, Montain SJ, Stachenfeld NS. Exercise and Fluid Replacement. Medicine and Science in Sports and Exercise, 39(2):377 – 390, 2007.
  8. Zello, G. Dietary Reference Intakes for the macronutrients and energy: considerations for physical activity. Appl Physiol Nutr Metab, 31 (1): 74 – 9, 2006.
Last Updated on Tuesday, 26 January 2010 01:39
 
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