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NEWS RELEASE

For immediate release:
January 5, 2001

ACSM, AMERICAN DIETETIC ASSOCIATION, and DIETITIANS OF CANADA
RELEASE JOINT POSITION PAPER
Supports appropriate nutrition for athletes, citing energy needs, fluid intake, timing, and expert advice on supplements

INDIANAPOLIS--The American College of Sports Medicine (ACSM), in cooperation with the American Dietetic Association (ADA) and Dietitians of Canada, has released a joint position statement, Nutrition and Athletic Performance. Taking the position that physical activity, athletic performance and recovery from exercise are enhanced by optimal nutrition, the paper recommends appropriate selection of food and fluids, timing of intake and careful supplement choices.

The joint statement, published in Medicine & Science in Sports & Exercise®, the official monthly journal of ACSM, addresses critical areas of interest, which include the composition of an athlete's diet, energy balance and body composition, as well as special situations like supplement use. The paper makes general recommendations for normally active persons, male endurance athletes, and men and women athletes involved in weight-class sports. Athletes and their health care professionals will find guidance about negative energy balance, how low food intake can contribute to energy drain, and the resulting possibility of compromise to reproductive and bone health.

Body composition is often part of the perception of optimal exercise performance. The joint position stand notes that some sports dictate that athletes make changes in body weight and composition that may not be optimal for the athlete. The paper warns against dropping below five percent body fat for males and 12 per cent for female athletes. A description of body composition assessment techniques is accompanied by the error rates of each, leading to the advice that individual athletes should aim for a range rather than a specific percentage.

The paper states that although carbohydrates, proteins and fats all contribute to the energy burned during athletic performance, data are not available to suggest that an athlete needs a diet substantially different from that recommended for the general population. Both the Dietary Guidelines for Americans and the Nutrition Recommendations for Canadians state that 55-58 per cent of energy should come from carbohydrate, 12-15 per cent from protein and 25-30 per cent from fat. Specific guidelines for individual energy components should be based on body size, weight, body composition, the sport and gender of the athlete. Further, increasing protein intake probably won't add to lean tissue; there is a limit to the rate at which protein tissue can be accrued. Branched chain amino acids have not yet tested consistently, so their use is not recommended for performance enhancement. Fat intake should not be severely restricted; there is no data suggesting a performance benefit in consuming a diet with less than 15 per cent of energy from fat, compared with 20-25 per cent of energy from fat.

Energy production, hemoglobin synthesis, immune function, bone health and protection from oxidative damage are all affected by micronutrient intake. Intense exercise stresses metabolic pathways, thus higher intake of vitamins and minerals by the athlete may be needed. A lack of consensus as to the need for additional antioxidants leads the authors to note that supplementation of these nutrients is probably not necessary in most athletes if energy intake is adequate. Calcium, iron and zinc, however are often low in the diets of athletes, especially females. Women, especially distance runners and vegetarians, should be screened periodically to assess iron status. Iron deficiency anemia can take three to six months to reverse, so if interventions are indicated, they should begin before the condition develops.

Addressing hydration, the paper reiterates commonly known fluid balance information, recommending that athletes use beverages containing carbohydrates in concentration of four to eight percent when performing in intense exercise events. Plain water or sports drinks are appropriate for events lasting under one hour, however. Special environmental conditions such as excessive heat and humidity, cold and high altitudes require increased fluid intake to avoid dehydration. The degree of increased intake must take into account the athlete, the event, the duration and intensity of the event, and body composition, among other things.

Training diet recommendations, including pre-exercise, during, and post-exercise, should first be translated into food choices consistent with food preferences and training schedules, says the paper. Noting again that the training diet should incorporate the principles outlined in the Dietary Guidelines for Americans and Canada's Guide for Healthy Eating, the paper declares the fundamental difference between an athlete's diet and that of the general population to be fluid intake. Careful attention to the amount of fluid lost during exercise and the replacement of that fluid is essential to the athlete's health. Further, as energy requirement s increase, the athlete should first consume the maximum carbohydrate calories, then dairy and protein foods to make up for energy expenditure. In reference to timing, individual athletes vary. Some are able to consume and digest large meals within an hour of intense exercise, but others must pace ingestion throughout the day. Athletes in heavy training may need to eat more than three meals and three snacks a day; glycogen synthesis and repletion are accomplished more easily with ingestion of a meal or snack high in whole-food carbohydrate within an hour of the end of exercise.

Supplements and ergogenic aids are the center of controversy; the position stand notes that claims for the efficacy of these products pressures the scientific community to keep current on the science. Of course this is not always possible, so the athlete needs tools for evaluating claims, thus: research the validity of the claim, the quality of the evidence, the health and legal consequences. Four categories emerge: those that perform as claimed, those that may perform as claimed, those that do not perform as claimed and those that are dangerous and should not be used. A table of guidelines for evaluation accompanies the paper, along with one that offers guidelines to weight management strategies for athletes. The needs of the vegetarian athlete are discussed, with admonition to monitor iron status, especially in females, and a section on the roles and responsibilities of health care professionals rounds out the topics covered by this position stand.

The American College of Sports Medicine is the largest sports medicine and exercise science organization in the world. Nearly 18,500 members throughout the U.S. and the world are dedicated to promoting and integrating scientific research, education, and practical applications of sports medicine and exercise science to maintain and enhance physical performance, fitness, health, and quality of life.

NOTE: Medicine & Science in Sports & Exercise® is the official journal of the American College of Sports Medicine, and is available from Lippincott, Williams & Wilkins at 1-800-638-6423. For a complete copy of the Position Stand, visit ACSM online at www.acsm.org. To speak with a leading sports medicine expert on the topic, contact the Department of Communications and Public Information at 317-637-9200.