nutritional recommendations for the physically active person
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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 poundExpend 3500 kCal, lose 1 pound
Energy Balance
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
My Pyramid
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
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
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
Males 838 23 5 72
Protein Synthesis
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
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