Ch. 14 Performance Nutrition Flashcards
Performance nutrition
combination of strategies to enhance performance through specific food and nutrient choices, timing, and quantities
Carbohydrates
primary fuel source during activity; exercise while carbohydrate-depleted increases stress hormones and reduces immune function; consumed in grains, fruits and vegetables, legumes, dairy
Glycogen
carbohydrate stored within muscle and liver tissue; depleted over two hours of exercise, or a 15-hour fast
Fiber
non-digestible carbohydrate; soluble and insoluble types; beneficial for healthy gut and immune system function
Glycemic Index (GI)
rating of carbohydrates based on how rapidly they raise blood sugar; higher-GI carbs raise blood sugar faster
Glycogen supercompensation (carbohydrate loading)
can almost double muscle glycogen concentrations; most effective for intense endurance activities over 90 minutes; consume typical meals for 3 days followed by 3 days of a high-carb diet just before competition
Protein
supports growth and maintenance of body tissues; synthesizes enzymes, hormones, and other peptides; builds antibodies; maintains fluid and electrolyte balance, repairs exercise- associated muscle damage, provides energy and glucose; consumed in meat, poultry, fish, eggs, beans, nuts, dairy
Gluconeogenesis
metabolic pathway that generates glucose from non-carbohydrate substrates such as pyruvate, lactate, glycerol, and glucogenic amino acids
Whey proteins
collection of globular proteins isolated from whey, a by-product of cow’s-milk cheese making; highest biological value of any protein
Casein
predominate phosphoprotein accounting for nearly 80% of proteins in milk and cheese
Essential amino acids
must come from food; cannot be synthesized by the body
Daily Carbohydrate Intake Recommendations for Athletes
- Typical American Diet: 4-5 g/kg/d
- General training needs: 5-7 g/kg/d
- Endurance training needs: 7-10 g/kg/d
- Ultra-endurance training needs: 11 g/kg/d or more
Daily Protein Intake Recommendations for Athletes
- Moderately active adults: 0.8 g/kg/d
- Strength athletes: 1.6-1.7 g/kg/d
- Strength athletes (vegetarian): 1.7-1.8 g/kg/d
- Endurance athletes: 1.2-1.4 g/kg/d
- Endurance athletes (vegetarian): 1.3-1.5 g/kg/d
- All exercising individuals: 1.4-2.0 g/kg/d
Fats
maintain function and elasticity of cell membranes, support structure and function of nervous system, produce hormones, regulate body temperature, assist with vitamin and carotenoid absorption, protect vital organs; saturated, monounsaturated, and polyunsaturated types; consumed in meats, poultry, fish, oils
Daily Fat Intake Guidelines
- 20-35% of daily energy intake
- 10% from saturated fatty acids
- 10% poly-unsaturated fatty acids
- 10% mono-unsaturated fatty acids
- Very low fat (<15%) diets show no performance benefit
Micronutrients
vitamins and minerals; play key roles in metabolism, bone health, hemoglobin production, immune function, and protection from oxidative damage
Antioxidants
nutrients that help remove free radicals from the body and reduce oxidative stress; e.g., vitamins E and C, beta-carotene, selenium; can become toxic at high doses
Daily energy balance
when sufficient calories are consumed to match daily energy expenditure
Inter-day energy balance
body composition can be impacted by meal and snack frequency; avoid energy deficits throughout the day by consuming smaller, more frequent meals
Pre-exercise meal
should contain sufficient fluids to maintain hydration, be low in fat and fiber to encourage gastric emptying, be high in carbohydrates to optimize glycogen stores, contain moderate protein, and be made of familiar foods so as to not upset the stomach; consume meal with 200-300g carbs 3-4 hours before exercise
Sports drinks
drinks containing 4-8% carbohydrates improve performance; use before morning workouts and for athletic events lasting longer than 1 hour
Muscle fuel recovery
consume high-GI carbs and proteins in a 4:1 ratio within 30-45 minutes immediately after exercise to maximize glycogen replenishment, promote anabolic processes, and enhance recovery
Insulin
substance responsible for transporting glucose and amino acids into cells and initiating glycogen and protein synthesis; muscle cells are most insulin-receptive immediately after exercise
Dietary Reference Intake (DRI)
family of four nutrient reference values; RDA, AI, EAR, and TUL; primary goals are to prevent nutrient deficiencies and reduce risk of chronic diseases such as osteoporosis, cancer, and cardiovascular disease
Recommended Daily Allowance (RDA)
average daily dietary intake level that adequately meets nutrient requirements of nearly all healthy individuals in a particular life stage and gender group
Adequate Intake (AI)
used when an RDA cannot be determined; recommended intake value based on observed or experimentally determined nutrient intake estimates of a group of healthy people
Estimated Average Requirement (EAR)
used to assess dietary adequacy; basis for the RDA; daily nutrient intake value estimated to meet half of a healthy individual’s requirement
Tolerable Upper Level (TUL)
highest level of daily nutrient intake not likely to pose a risk of adverse health effects for almost all individuals in the general population; potential risk of adverse effects increases as intake increases above TUL
Performance effects of hydration
dehydration of greater than 2% body mass can decrease aerobic exercise performance, visuomotor tracking, short-term memory, response time, coordination, attention, and mental focus
Symptoms of dehydration
thirst, discomfort, fatigue, flushed skin, muscle cramps, apathy, dizziness, headache, nausea, vomiting, chills, shortness of breath
Hyponatremia
abnormally low levels of blood sodium; a.k.a. water intoxication; caused by overdrinking hypotonic fluids combined with excessive sodium loss (sweat)
Fluid Replacement Guidelines
- Before Exercise: 14-22 oz. Fluid 2 hours before exercise
- During Exercise: 6-12 oz. Water or sports drink every 15-20
min of exercise - After Exercise: 16-24 oz. Water or sports drink for every
pound of body weight lost during exercise
Appropriate Nutritional Discussion Topics for the Sports Performance Professional
• Food preparations methods
• Healthy snacks
• Statistical information on the relationship between
chronic disease and the excesses of deficiencies of specific
nutrients
• Vitamins and minerals as essential nutrients
• Food guidance systems: USDA MyPlate (www.choosemyplate.gov)
• Carbohydrate, protein, and fat basics
• Nutrients contained in foods or supplements
• Importance of water and hydration status
Eicosanoid
Signaling molecules made by oxygenation of 20-carbon essential fatty acids (EFAs). They exert complex control over many bodily systems, mainly in inflammation or immunity, and as messengers in the central nervous system.
High-glycemic- index carbohydrates
Carbohydrates that break down rapidly during digestion, releasing glucose rapidly into the bloodstream.
To reduce post-exercise soreness, it is best to consume which nutrient?
Branch chain amino acids
For supercompensation to happen, athletes should progress to a higher carbohydrate diet for how many days before competition?
3 days
For which time frame might athletes require a higher protein intake due to accelerated hypertrophy rates?
The first 3-6 months of training
Greater disturbance in which of the following functions can result when an athlete competes in a carbohydrate depleted state?
Immune function
What is the term used when calories expended exceed calories ingested?
Negative energy balance
Consuming which antioxidant nutrient may help reduce muscle soreness and damage caused by exercise-associated oxidative stress?
Vitamin C
To maximize recovery, athletes should consume which ratio of carbohydrates to protein 30-45 minutes after exercise?
4:1
During which time frame of endurance exercise does fat oxidation become stimulated?
After 15-20 minutes
At what percent of dehydration will aerobic exercise performance decrease?
2%
Which time frame requires refueling to prevent liver glycogen depletion?
15 hours
Which of the following is defined as a fatty acid that has one double bond?
Monounsaturated
How many grams of carbohydrates should athletes consume for optimal performance?
6-10g/kg/day
Which of the following is appropriate for sports performance professionals to discuss with athletes?
USDA MyPlate
The production of hormones and absorption of many vitamins are two important roles of which nutrient?
Fat
The ability to calculate, counsel, or prescribe an individualized nutrition or weight management plan is best referred to which professional?
Registered dietitian
