Academy of Nutrition and Dietetics Nutrition and Athletic Performance 2016 Guidelines

Definition

Purpose

Description

• 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

• 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

• 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

• vegetarians
• altitude
• extreme environments including heat and cold

• “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.

• 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.