Richard Stockton College Athletic Training

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A periodic Newsletter that addresses the Nutritional aspects
of athletic competition.


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Nancy Brinch, MS, RD, LSW, is Richard Stockton College's campus nutritionist. She obtained her BS in Food and Nutriton from the Univ. of Delaware and her Master's in Nutrition from Penn State Univ.

She provides individual, confidential nutritional counseling to students. Her service is free for RSC students. For appointments call extension 5740. Nancy Brinch can be contacted at Nancy.Brinch@stockton.edu
Dietary Supplements: Factually Speaking

By Nancy Brinch, MS, RD, LSW

Athletes often take dietary supplements in the hope that supplements will give them a competitive edge which will improve their performance. These dietary supplements include vitamins and minerals as well as ergogenic aids. This article will address some of the ergogenic aids used by athletes.

The term ergogenic means "work-producing." Since competitions can be won by a fraction of a second, athletes may take these supplements in an attempt to increase speed, enhance muscle mass, improve endurance, speed recovery time, and reduce body fat. Most of these supplements have very little scientific evidence supporting their claims. Much of the research on these products is of poor quality and has not been published in reputable, peer-reviewed journals.

The word "natural" on a supplement label often leads an athlete to think this means the product is "safe" and "legal." This can be a dangerous assumption. Supplement manufacturers do not have to prove their products are safe, effective or potent before they put the products on the market. Unlike medications, dietary supplements do not have to be approved by the Food and Drug Administration for safety or effectiveness. Manufacturers are not supposed to make unsubstantiated claims about their products, but they get around this requirement by placing the following disclaimer on the label: "This statement has not been evaluated by the Food and Drug Administration. This product is not intended to diagnose, treat, cure or prevent disease." Often this disclaimer is placed on the back of the label in small print. An additional risk for collegiate athletes is these products may contain banned substances that could cause the failure of a drug test. Buyer beware!!!!

Amino acids
Branched chain amino acids (BCAA): Claims for BCAA tout they can prevent fatigue and increase aerobic endurance. Scientific data does not show any performance enhancing benefit from taking BCAA. Consuming large amounts of BCAA during exercise can slow water absorption from the gut and cause gastrointestinal pain. Adequate quantities of BCAA can be obtained from food. Supplements may not be safe or effective. SUPPLEMENTS NOT RECOMMENDED

Arginine, lysine, ornithine: Claims for these amino acids include increased muscle mass, decreased body fat, and increased human growth hormone (hGH) secretion. Scientific research has shown that supplementation with these amino acids does not have any impact on body composition or on hGH levels. Consuming large amounts of any single amino acid can interfere with the absorption of other amino acids, cause gastric distress, and result in metabolic imbalances. Sufficient amounts of amino acids can be found in food (see previous article Protein: Power or Propaganda). SUPPLEMENTS NOT RECOMMENDED

Beta-Hydroxy-Beta-Methylbutyrate (HMB)

Claims for this ergogenic aid include increased muscle mass, decreased body fat, and increased strength and power. The limited research on HMB was performed by the laboratory that developed it. This research showed no statistically significant increase in muscle mass in subjects who took HMB compared with control subjects although strength did increase in subjects who took HMB. No other research has reproduced these results. HMB is expensive, and its potential benefits are questionable. SUPPLEMENT NOT RECOMMENDED

Chromium picolinate (CrPl)
Promoters claim CrPl can increase muscle mass, decrease body fat, and it is a safe alternative to anabolic steroids. These claims are based on research reported in 1989 that has been widely criticized for its poor quality. Subsequent research has shown no change in strength or body composition after taking CrPl. Subjects taking CrPl excreted more chromium in their urine. The amount of chromium used in these studies (200 micrograms) is considered safe (National Research Council considers 50-200 mcg. of chromium to be safe and adequate.) This amount of chromium can be obtained from foods such as nuts, whole grains, cheese, asparagus and brewer's yeast. In 1996 the Federal Trade Commission ordered the three largest distributors of CrPl to stop making unsubstantiated claims about CrPl (such as increased muscle mass, decreased body fat, and increased energy.) SUPPLEMENT NOT NECESSARY

L-Carnitine
Claims for L-carnitine include increased use of fatty acids for fuel, decreased body fat, and increased endurance. Research on this supplement shows no beneficial impact on exercise performance. The supplement appears to be safe, although concerns have risen over the possible contamination with D-carnitine that can deplete L-carnitine in the body. Carnitine is found in meats, and it is synthesized in the body. SUPPLEMENT NOT RECOMMENDED

Conjugated LinoleicAcid (CLA)
Most of the research on CLA has been conducted on animals. Mice fed CLA have significantly less body fat and increased muscle tissue compared with controls. Until well-controlled studies have been undertaken in humans CLA supplements are not warranted. No adverse reactions to CLA supplementation have been reported. SUPPLEMENT NOT RECOMMENDED AT THIS TIME

Pyruvate
Promoters of pyruvate claim it increases aerobic endurance, increases metabolic rate and decreases fat mass. Only two research studies have shown any evidence of improved endurance after taking pyruvate. In both studies untrained male subjects were given high doses of pyruvate plus dihydroxyacetone. These studies should not be used to justify supplementation because 1) the subjects were given amounts of pyruvate much higher than the amounts found in commercial preparations, 2) many commercial supplements do not contain dihydroxyacetone which was used in the research and 3) the subjects experienced side effects such as intestinal gas, flatus, and diarrhea. SUPPLEMENT NOT RECOMMENDED

Source: Rosenbloom CA, ed. Sports Nutrition: A Guide for the Professional Working with Active People. Chicago, IL: American Dietetic Association Sports, Cardiovascular, and Wellness Nutritionists Dietetic Practice Group; 2002.
   
   
 
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