Definition
In 2016, the American College of Sports Medicine (ACSM), the Academy of Nutrition and Dietetics, and Dieticians of Canada issued a joint 28-page position paper detailing evidence-based recommendations for calorie, nutrient, and fluid requirements for active adults and competitive athletes. The guidelines included recommendations for special populations and environments.
Purpose
The 21st century has seen a major increase in nutritional research for optimizing health and athletic performance, along with increased marketing of nutritional sports supplements. Recent publications include research studies and reviews, consensus statements from sports organizations, and qualifications and accreditations for sports nutritionists and dieticians, as well as extensive coverage in popular media. The ACSM, the Academy of Nutrition and Dietetics, and Dieticians of Canada support nutritional strategies for optimizing health and enhancing athletic training and competitive performance and recovery, but they determined that the flood of confusing and contradictory information demanded the formulation of detailed, evidence-based guidelines concerning appropriate types, amounts, and timing of foods, fluids, and dietary supplements based on individual body types and athletic performance requirements.
The guidelines were prepared for use by the public, as well as by members of the three supporting organizations, and by other organizations, government agencies, and industry. The position paper affirms that athletes should consult a registered dietitian or nutritionist, including Certified Specialists in Sports Dietetics in the United States and Canada, for the development of personalized nutrition plans. The joint position statement and guidelines remain in effect until the end of 2019.
Description
The 2016 guidelines were the result of independent literature reviews by the three authors—one from each of the three organizations—and a systematic review using the Academy of Nutrition and Dietetics's Evidence Analysis Process and Library. The position paper and guidelines were reviewed by experts from each of the three organizations and by the Academy Positions Committee Workgroup. They include 157 literature references.
The evidence-based analysis covered the period from March 2006 through November 2014. Each of the 11 conclusions—2 for energy balance and body composition, 6 for recovery, and 3 for training—were assigned a grade based on analysis and evaluation of the research evidence:
- Grade I: good evidence
- Grade II: fair evidence
- Grade III: limited evidence
- Grade IV: expert opinion only
- Grade V: not assignable due to of lack of evidence
Themes
The guidelines address four major themes:
Nutrition for athlete preparation examines and calculates energy requirements, balance, and availability. This theme also covers body composition and sports performance, including:
- methods of assessing body composition
- altering body composition and weight
- nutrient requirements for energy pathways and training adaptations
- carbohydrate requirements based on exercise intensity, timing of intake, and fueling strategies
- protein requirements, timing of intake, and optimal sources of protein
- fat requirements
- alcohol consumption
- micronutrient requirements, especially iron, vitamin D, calcium, and antioxidants
Nutritional strategies for optimizing performance and recovery include:
- eating before, during, and after training and events
- hydration guidelines for fluid and electrolyte balance before, during, and after exercise
- carbohydrate intake guidelines, including achieving adequate stores of muscle glycogen
- protein intake guidelines
- dietary supplements and sports foods for which there may be at least some evidence of usefulness, including vitamin, mineral, and fatty acid supplements; creatine; caffeine; sodium bicarbonate; beta-alanine; nitrate; sports drinks, bars, candy, and gels; and electrolyte, protein, and liquid-meal supplements
Special populations and environments include:
- vegetarians
- altitude
- extreme environments including heat and cold
Key recommendations
The 2016 guidelines are quite detailed, covering training and competition for a range of sports. They specify recommended amounts and timing of intake for different nutrients for which there is evidence of enhanced performance and recovery, without specifying types of foods. The guidelines emphasize that recommendations must be personalized for individual athletes in consultation with a sports dietician.
Guideline fundamentals include the following:
- “The primary goal of a training diet is to provide nutritional support to allow an athlete to stay healthy and injury-free while maximizing the functional and metabolic adaptations to a periodized exercise program that prepares him or her to better achieve the performance demands of the event”(Thomas, et al. 2016b, 521–2).
- Maintaining health and maximizing the effects of training require adequate amounts and timing of energy intake during high-intensity and long-duration workouts.
- Energy availability is fundamental to health and performance.
- “Low energy availability can result in unwanted loss of muscle mass; menstrual dysfunction and hormonal disturbances; suboptimal bone density; an increased risk of fatigue, injury, and illness; impaired adaptation; and a prolonged recovery process.”
- Health and performance can be affected by the type, amount, and timing of food, fluid, and supplement intake, as well as the specifics of training regimens and competition, such as strategies for training hard and recovering quickly versus strategies for targeting and “enhancing the training stimulus or adaptation” (510).
- Nutritional support needs to accommodate both the requirements of daily training sessions and overall nutritional goals.
- Recommendations for the intake of calories, nutrients, and fluids are different before, during, and after sporting activities, both for active adults and for competitive athletes, and follow different cycles during the training calendar.
- Recommendations should be individualized based on the athlete's health; nutrient requirements; physical characteristics, such as body size, shape, and composition including muscle mass and body fat, which are dependent on sex, heredity, and growth; sport- or event-specific requirements; performance goals; food preferences; and individual challenges.
- Nutrition standards during training should focus on developing metabolic efficiency and flexibility, whereas competition nutrition strategies should focus on fuel storage to meet the demands of the event and support cognitive function.
- Any required changes in body composition should occur well before competition. Any practices that result in inappropriately low energy availability and/or psychological stress must be avoided.
Specific nutritional recommendations include the following:
- The recommended carbohydrate intake range is typically 3–10 g/kg (0.1–0.35 oz./2.2 lb.) of body weight (BW) per day, depending on the activity, and up to 12 g/kg (0.4 oz./2.2 lb.) BW for extreme or prolonged exercise, depending on the fuel demands and goals of training and competition. Carbohydrate intake may require modifications, depending on weekly and seasonal schedules.
- Typical recommendations for protein intake range from 1.2–2.0 g/kg (0.04–0.07 oz./2.2 lb.) BW per day, with 0.3 g/kg (0.01 oz./2.2 lb.) BW of high-quality protein, typically from foods, at regular intervals after exercise and throughout the day.
- Fat intake should range from 20%–35% of total calories.
- Athletes' diets should provide at least the recommended dietary allowance (RDA) or adequate intake (AI) of all micronutrients. Restricting energy intake, following severe weight-loss strategies, or eliminating complete food groups pose a risk of micronutrient deficiencies.
- Competition nutrition must address factors that cause fatigue or diminishment of skill or concentration. For example, for events that depend on muscle carbohydrates, meals in the preceding days should provide sufficient carbohydrate to build up glycogen stores in muscle. Tapering exercise and 7–12 g/kg (0.25–0.4 oz./2.2. lb.) BW/day can normalize glycogen levels within about 24 hours.
- Fluids and fuels consumed one to four hours before an event should contribute to carbohydrate stores, ensure appropriate hydration, and maintain gastrointestinal comfort. Specific types and amounts of food and fluid and their timing should be individualized and tested before the event.
- Appropriate fluid intake before, during, and after training and competition is essential for optimizing health and performance. Fluid intake should be individualized and should compensate for sweat loss, because dehydration or under-hydration can impair performance and increase one's perception of exertion. Following exercise, fluid balance should be restored by drinking about 125%–150% of the fluid deficit, such as 1.25–1.5 L (1.32–1.59 qt.) per kg (2.2 lb.) of lost body weight.
- Additional carbohydrates may be consumed during events longer than 50 minutes—typically 30–60 g (1–2 oz.) per hour for muscle fuel and maintaining blood glucose levels. Up to 90 g (3 oz.) per hour may improve performance in events exceeding 2.5 hours. During high-intensity events of 45–75 minutes, frequent exposure of the mouth and oral cavity to small amounts of carbohydrate can stimulate the brain and central nervous system and improve performance, even though carbohydrate intake is not metabolically required. New but convincing evidence indicates that brain sensing of carbohydrates and possibly other nutrition in the oral cavity enhances well-being, which can increase effort even during shorter events.
- Rapid recovery between training sessions or events requires carbohydrate intake of about 1.0–1.2 g/kg (0.03–0.04 oz./2.2 lb.) per hour beginning in the early recovery phase and continuing for four to six hours for optimal synthesis of muscle glycogen. Recovery also requires early intake of 0.25–0.3 g/kg (0.008–0.01 oz./2.2 lb.) BW of high-quality protein to supply amino acids for repairing and building muscle and possibly increasing glycogen storage under conditions of suboptimal carbohydrate intake.
- Vitamin and mineral supplements are generally unnecessary with a high-energy diet that includes a variety of nutrient-dense foods. Any supplementation should be individualized to treat or prevent specific deficiencies. Supplements are of the most value when added to an appropriate eating plan.
- Any sports foods or supplemental products should be carefully evaluated for safety, effectiveness, potency, and compliance with antidoping and legal regulations.
- Vegetarian athletes may be at risk for low intake of energy, protein, fat, creatine, carnosine, omega-3 fatty acids, and micronutrients such as iron, calcium, riboflavin, zinc, and vitamin B12.
See also Nutrient timing
.
Resources
PERIODICALS
Thomas, D. Travis, Kelly Anne Erdman, and Louise M. Burke. “American College of SportsMedicine Joint Position Statement: Nutrition and Athletic Performance.” Medicine & Science in Sports & Exercise 48, no. 3 (March 2016a): 543–68.
Thomas, D. Travis, Kelly Anne Erdman, and Louise M. Burke. “Position of the Academy of Nutrition and Dietetics, Dietitians of Canada, and the American College of Sports Medicine: Nutrition and Athletic Performance.” Journal of the Academy of Nutrition and Dietetics 116, no. 3 (March 2016b): 501–28. http://www.eatrightpro.org/~/media/eatrightpro%20files/practice/position%20and%20practice%20papers/position%20papers/nutritionathleticperf.ashx (accessed February 25, 2017).
ORGANIZATIONS
Academy of Nutrition and Dietetics, 120 South Riverside Plz., Ste. 2190, Chicago, IL, 60606-6995, (312) 899-0040, (800) 877-1600,
http://www.eatright.org
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American College of Sports Medicine, 401 West Michigan St., Indianapolis, IN, 46202-3233, (317) 6379200, Fax: (317) 634-7817,
http://www.acsm.org
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Dietitians of Canada, 480 University Ave., Ste. 604, Toronto, Canada, ONT, M5G 1V2, (416) 596-0857, Fax: (416) 596-0603, contactus@dietitians.ca,
http://www.dietitians.ca
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This information is not a tool for self-diagnosis or a substitute for professional care.