Clinical Practice Guidelines: Nutrition for the Athlete

Transcription

1 Clinical Practice Guidelines: Nutrition for the Athlete DAILY MACRONUTRIENT AND ENERGY NEEDS Energy and macronutrient needs vary for each individual depending on the intensity, frequency, duration, and volume of training. Volume--the amount of time that an individual performs an activity--and type--spanning from low-intensity, endurance types to highintensity, power-based types--have the largest effect on macronutrient needs. Many sports do not fall exclusively into either of these categories but rather fall on a continuum. By volume(1-4) General exercise (30-40 minutes, 3 times per week) Moderate (2-3 hours per day, 5-6 times per week) High volume intense training (3-6 hours per day, 5-6 days per week) Elite (i.e. Tour de France) Energy kcal/kg/day kcal/kg/day kcal/kg/day kcal/kg/day Carbohydrates Protein Fat 3, By type(1-4) Endurance athletes (marathon, triathlon, cycling, swimming) Strength and power athletes High volume, intense activities Energy Highly dependent on total daily energy expenditure, type of sport, environmental conditions, and gender Carbohydrates Protein Fat 3, Include pre- and post-training carbohydrates; if exercise lasts longer than 60 minutes, add carbohydrates during physical activity. (1) 2 Focus on protein quality and amino acid content; use supplements where needed. (1) 3 Daily fat intake remains relatively stable across types and volume of exercise; while higher fat diets may be necessary for high-volume, high-intensity athletes (i.e. those training for an Ironman or Tour de France), it should not be done at the expense of carbohydrate or protein intake. Focus on increasing intake of unsaturated and essential fatty acids. (1,2,3) 4 Based on available data, high-fat diets are not recommended for athletes. (4,5,6)

2 Fueling Before, During, and After Exercise Fueling before, during, and after exercise accomplishes different goals to optimize sports performance. Before exercise, carbohydrates should be prioritized to boost blood glucose levels and top off glycogen stores; moderate amounts of protein may be added to spare glycogen and improve endurance. During exercise, carbohydrates should also be prioritized to maintain blood glucose levels especially in events lasting longer than 60 minutes. After exercise, a mix of carbohydrates and protein should be prioritized to replace glycogen stores and stimulate recovery. (3) Before 1 During After Carbohydrates 1-2 g/kg 3-4 hours <60 min None g/kg during first before event; another light snack (25-30 g) hours g/hour or 0.7 g/kg/hour 30 minutes; again every 2 hours for minutes before exercise 2 >2.5 hours 90 g/hour hours Protein g/kg BW 3- No recommendations g/kg 4 4 hours before event; another light snack (5-10 g) minutes before exercise 2 Fat Minimal amounts 5 Avoid 6 No recommendations 7 1 Meals and snacks consumed before an event should be familiar to the athlete; ideally, the athlete has experimented with types, amounts, and timing of meals and has found an individualized plan. (1) 2 Research suggests that it takes roughly 4 hours for carbohydrates to be digested and stored as muscle and liver glycogen. Adding another light snack minutes before exercise may help increase carbohydrate availability. (2) 3 Although recent literature suggests that consuming small amounts of protein along with carbohydrates during exercise may improve endurance, spare glycogen, reduce muscle damage, and enhance recovery, there are currently no guidelines for protein supplementation during exercise. (1) Ingestion of ~20 grams of protein within 30 minutes of exercising may maximize muscle protein synthesis. (2) 4 Current guidelines recommend aiming to eat a mix of carbohydrates and protein in a ratio of 3-4:1. For most individuals, this can be accomplished by choosing a snack or meal with grams of carbohydrates and 6-20 grams of essential amino acids; resistance or strength athletes may benefit from higher amounts (20-25 grams) of protein. (1)

3 5 There is currently no evidence to suggest that pre-exercise ingestion of fat improves performance. (1) 6 Ingesting fats during exercise may promote gastrointestinal distress and delay gastric emptying; in addition, because of their slower oxidation rate, they cannot be used immediately as a fuel source. (7) 7 There are currently no recommendations regarding fat intake post-exercise; while it is not necessary to avoid it, protein and carbohydrate intake should be prioritized (1) Hydration Performance is impaired significantly when 2% or more of body weight is lost through sweat. Individual fluid and electrolyte needs vary widely and are also influenced by such factors as environment and exercise duration and intensity. Obtaining pre- and postexercise weight measurements can be helpful in determining individualized fluid needs. (8) Fluid and electrolyte guidelines before, during, and after exercise (1,2,8) Fluid requirements 5-7 ml/kg starting 4 hours before; if urine is darkly colored, another 3-5 ml/kg 2 hours before event Electrolytes Before During After L/hour; 6-8 oz every 5-20 minutes 1.5 L per kg weight lost Use of supplements with added electrolytes are indicated in exercise lasting longer than two hours, during extreme weather, and in individuals with an increased sweat rate. Choose drinks or solutions with ~20-30 meq/l ( mg) sodium and ~2-5 meq/l ( mg) potassium; specific amounts depend on duration and intensity 1 1 For comparison, eight ounces of Gatorade contains mg sodium and mg potassium; one half tablet of Nuun Active Hydration has 180 mg sodium and 50 mg potassium. Suggestions for an 80-kg (176-lb) athlete Exact amounts of energy, carbohydrates, protein, and fat should be tailored to each individual and should be tested before tournaments at practices and workouts. Daily intakes of energy and each macronutrient will also depend heavily on the volume and intensity of the workout done each day.

4 Total Daily Intake Energy 4,000-6,400 kcal Carbohydrates g Before exercise g 3-4 hours before + additional g min before Protein g g 3-4 hours before + additional 5-10 g min before During exercise g/hour Small amounts After exercise g during first 30 minutes; again every 2 hours g Fat g Minimal amounts Avoid No recommendations

5 References 1. Potgieter S. Sport nutrition: A review of the latest guidelines for exercise and sport nutrition from the American College of Sport Nutrition, the International Olympic Committee and the International Society for Sports Nutrition. S Afr J Clin Nutr. 2013;26(1): Kreider RB, Wilborn CD, Taylor L, Campbell B, Almada AL, Collins R, et al. ISSN exercise & sport nutrition review: research & recommendations. J Int Soc Sports Nutr. 2010;7:7. 3. Rodriguez NR, DiMarco NM, Langley S. American College of Sports Medicine position stand. Nutrition and athletic performance. Med Sci Sports Exerc. 2009;41(3): Maughan R, Burke L. Nutrition for athletes: A practical guide to eating for health and performance. Nutrition Working Group of the International Olympic Committee. April Burke LM, Kiens B. Fat adaptation for athletic performance: the nail in the coffin? J Appl Physiol. 2006;100: Kiens B, Helge JW. Adaptations to a high fat diet. In: Maughan RJ, ed. The encyclopaedia of sports medicine: An IOC Medical Commission publication. New York City, NY: John Wiley & Sons, 2008: Berg JM, Tymoczko JL, Stryer L. Fuel choice during exercise is determined by intensity and duration of activity. In: Biochemistry, 5 th ed. New York, NY: W H Freeman, Exercise and Fluid Replacement Position Stand, American College of Sports Medicine, Med Sci Sports Exer. 2007:39;