270 likes | 366 Views
Nutritional Recommendations for the Physically Active Person. Chapter 7 Part 1. The Optimal Diet. Supplies required nutrients in adequate amounts for: Tissue maintenance and repair Growth without excess energy intake . The Optimal Diet. Proper nutrition helps:
E N D
Nutritional Recommendations for the Physically Active Person Chapter 7 Part 1
The Optimal Diet • Supplies required nutrients in adequate amounts for: • Tissue maintenance and repair • Growth without excess energy intake
The Optimal Diet • Proper nutrition helps: • Improve athletic performance • Optimize programs of physical conditioning • Improve recovery from fatigue • Avoid injury
Energy Balance Equation • Body mass remains constant • Caloric intake equals caloric expenditure. • 3500 kCal approximately equals 1 lb of stored body fat. • Consume 3500 extra kCal, gain 1 pound • Expend 3500 kCal, lose 1 pound
Principles of Good Eating • Variety • Creates a diet with sufficient amounts of required nutrients. • Balance • Intake of nutrients from the major food groups. • Moderation • Planning to maintain a balanced nutrient intake throughout the day.
My Pyramid • www.mypyramid.gov • Can be personalized • Based on age, sex, and level of daily exercise • Figure is to emphasize at least 30 minutes of moderate to vigorous daily physical activity • Based on the 2005 Dietary Guidelines for Americans
Dietary Guidelines for Americans • Control caloric intake to manage body weight. • Consume a variety of foods. • Within the basic food groups • Increase daily intake of: • Fruits, vegetables, whole grains, and nonfat or low-fat milk and milk products. • Choose fats wisely for good health. • Limit saturated fats and trans fats.
Dietary Guidelines for Americans (cont.) • Choose carbohydrates wisely for good health. • Choose and prepare foods with little salt. • If you drink alcoholic beverages, do so in moderation. • Be physically active every day. • Keep food safe to eat.
Serving Size Versus Portions • The USDA defines a standard serving of pasta as one-half cup. • The FDA, which regulates food labels, claims a standard serving is 1 cup. • Typical restaurant pasta portion averages about 3 cups. • Equal to 6 servings according to MyPyramid
Mediterranean and Vegetarian Diet Pyramids • Mediterranean • Emphasizes fruits, nuts, vegetables, legumes, all manner of unrefined grains, and protein derived from fish, beans, and chicken • High monounsaturated fatty acid content • Vegetarian • Consists of foods from the plant kingdom
Protein Intake - Physically Active • RDA = 0.8 g/kg of body mass • Is it enough? • Eating a high-carbohydrate diet • Adequate to conserve muscle protein during intense training.
Protein Intake - Physically Active • Those in endurance training • 1.2 to 1.6 g/kg/day of high-quality protein • Those who resistance train • 1.0-1.6 g/kg of body mass.
Protein Metabolism • Enter (AA pool) • Dietary • Tissue breakdown • Nonessential – formed in body
Protein Metabolism • Exit - (AA pool) • Into gut • Into tissue structure • AA N2 lost in urine, sweat • Oxidized • Stored as CHO, fat
Protein Synthesis • Protein synthesis • Gene expression • Each gene directs synthesis of one protein • DNA is transribed to mRNA (messenger RNA) • mRNA takes the message out to the ribosome • tRNA (transfer RNA) is also required to make the new molecule
Protein Needs-Physical Exercise • Rodent muscle • 113% increase in muscle urea N2 content • 1 h running • Increased degradation of muscle protein • Kasperek & Snider, 1989 • Significant muscle damage • Armstrong et al. 1983 • Significant eccentric component
Protein Needs-Physical Exercise • Research questions • Does increased protein intake reduce this damage? • Does increased protein intake speed the repair processes?
Protein Needs-Physical Exercise • Branched chain amino acids (BCAA) • Predominantly oxidized during endurance exercise • Related to availability of BCAA and inversely proportional to glycogen availability • Increased BCAA/glycogen at end of prolonged run • Fasting state
Branched Chain Amino Acids • Daily requirements • Single bout of exercise • 2 h 55% VO2max • Oxidation rate equivalent to 90% daily requirement
Endurance Exercise and Protein Metabolism • Energy requirement – 1 h 65-75%VO2max • kcal/h %fat %pro %CHO • Males838 23 5 72
High Protein Intake • Concerns? • Kidney failure • Rodents – 80% protein • No problems • Absence of reports of kidney problems in weight lifter/body builders • High protein diets 20-30 years • Excess N2 not a problem – In healthy individuals
High Protein Intake • Concerns? • Dehydration • Excess water loss with nitrogen excretion • Sweat loss • Proper rehydration – monitor body weight