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Ch12 Fitness Sports


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Ch12 Fitness Sports

  1. 1. Chapter 12 Nutrition: Fitness and Sports Lecture and Animation PowerPoint Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display. To run the animations you must be in Slideshow View . Use the buttons on the animation to play, pause, and turn audio/text on or off. Please Note : Once you have used any of the animation controls , you must click in the white background before advancing to the next slide.
  2. 2. Physical Fitness <ul><li>“ The ability to perform moderate to vigorous activity without undue fatigue” </li></ul><ul><li>Fat usage by the body </li></ul><ul><ul><li>Increased physical fitness means improved usage of fat for energy </li></ul></ul>
  3. 3. Benefits of Physical Activity
  4. 4. Nutrition and Physical Activity <ul><li>Only 15% of adults are regularly physically active </li></ul>NUTRITION (intake) Physical Performance Nutrient Use
  5. 5. Healthy People 2010 <ul><li>Decrease inactivity in adults by 50% </li></ul><ul><li>Increase the number of people who exercise regularly </li></ul><ul><li>Increase the development of vigorous physical activity </li></ul><ul><li>Increase adults who perform muscular strength and endurance activities </li></ul>
  6. 6. Beginning an Exercise Program <ul><li>Start out slowly </li></ul><ul><li>Vary your workout — Make it fun </li></ul><ul><li>Include others — Keep accountable </li></ul><ul><li>Set attainable goals </li></ul><ul><li>Set aside specific time </li></ul><ul><li>Reward yourself </li></ul><ul><li>Focus on long-term and not on occasional setbacks </li></ul>
  7. 7. 2005 Dietary Guidelines for Americans <ul><li>30 minutes/day physical activity </li></ul><ul><ul><li>Reduce risk of chronic disease </li></ul></ul><ul><li>60 minutes/day physical activity </li></ul><ul><ul><li>Manage body weight and prevent weight gain </li></ul></ul><ul><li>90 minutes/day physical activity </li></ul><ul><ul><li>Sustain weight loss </li></ul></ul>
  8. 8. Fuel for Muscle Work <ul><li>ATP </li></ul><ul><li>Chemical energy </li></ul><ul><ul><li>Used by cells for muscle contractions </li></ul></ul><ul><li>Only small amount is stored in resting cells </li></ul><ul><ul><li>2-4 seconds worth of work </li></ul></ul><ul><li>Other sources of energy are needed </li></ul>
  9. 9. Phosphocreatine (PCr) <ul><li>High-energy compound </li></ul><ul><ul><li>Formed and stored in muscle cells </li></ul></ul><ul><ul><li>PCr + ADP Cr + ATP </li></ul></ul><ul><li>Activated instantly </li></ul><ul><ul><li>Replenishes ATP </li></ul></ul><ul><li>Sustains ATP (work) for a few minutes </li></ul>
  10. 10. Breakdown of ATP and Cross-bridge Movement During Muscle Contraction
  11. 11. Anaerobic Glycolysis <ul><li>Limited oxygen — Intense physical activity (sprinting) </li></ul><ul><li>Pyruvate is converted to lactate </li></ul><ul><li>Produces 2 ATP per glucose </li></ul><ul><ul><li>~5% of energy potential </li></ul></ul><ul><li>Replenishes ATP quickly </li></ul><ul><li>Cannot sustain ATP production </li></ul><ul><ul><li>30 seconds to 2 minutes of work </li></ul></ul><ul><li>Lactate build-up </li></ul><ul><ul><li>Changes acidity that inhibits glycolysis enzymes </li></ul></ul>
  12. 12. How Glycolysis Works
  13. 13. Aerobic Glycolysis <ul><li>Plenty of oxygen available </li></ul><ul><li>Low to moderate intensity (jogging) </li></ul><ul><li>Produces 36-38 ATP per glucose </li></ul><ul><ul><li>95% of energy potential </li></ul></ul><ul><li>ATP replenished slowly </li></ul><ul><li>Sustained ATP production </li></ul><ul><ul><li>2 minutes to 3 hours of work </li></ul></ul>
  14. 14. Glucose Utilization
  15. 15. Energy Sources for Prolonged Exercise
  16. 16. Glycogen <ul><li>Temporary storage of glucose in liver and muscle </li></ul><ul><li>Muscle glycogen </li></ul><ul><ul><li>Used only by that muscle </li></ul></ul><ul><li>Liver glycogen released into bloodstream </li></ul><ul><li>During low to moderate intensity </li></ul><ul><ul><li>Can sustain work for up to 2 hours </li></ul></ul><ul><li>“ Bonking” </li></ul><ul><ul><li>Depleted glycogen </li></ul></ul><ul><ul><li>Work at ~50% of maximal capacity </li></ul></ul>
  17. 17. ATP Formation
  18. 18. Maintaining Normal Blood Glucose Level <ul><li>Important </li></ul><ul><ul><li>For activity lasting longer than 20-30 minutes </li></ul></ul><ul><li>Intake of 30-60 gm carbohydrates per hour </li></ul><ul><ul><li>During strenuous endurance activity </li></ul></ul><ul><ul><li>Delays fatigue by 30-60 minutes </li></ul></ul>
  19. 19. Fat Fuel (Fatty Acid) <ul><li>Majority of stored energy in the body </li></ul><ul><li>Fatty acids </li></ul><ul><ul><li>Converted to ATP by muscle cells </li></ul></ul><ul><li>12 ATP produced </li></ul><ul><ul><li>Per each turn of the Citric Acid Cycle </li></ul></ul><ul><ul><li>108 ATP for each 16 C fatty acid chain </li></ul></ul><ul><li>Trained muscles </li></ul><ul><ul><li>Have more mitochondria </li></ul></ul><ul><ul><li>Have greater ability to use fat as fuel </li></ul></ul>
  20. 20. Fat Fuel <ul><li>Rate of fat use </li></ul><ul><ul><li>Dependent on concentration of fatty acids in the bloodstream </li></ul></ul><ul><li>Prolonged exercise </li></ul><ul><ul><li>Fat becomes main fuel source </li></ul></ul><ul><li>Intense activity </li></ul><ul><ul><li>Fat is not a major source of fuel </li></ul></ul><ul><ul><li>Requires more oxygen for aerobic breakdown (than glucose) </li></ul></ul>
  21. 21. Protein — Minor Source of Fuel <ul><li>During rest and low/moderate exercise </li></ul><ul><ul><li>Provides 2%-5% of energy needs </li></ul></ul><ul><li>During endurance exercise </li></ul><ul><ul><li>Provides 10%-15% of energy needs </li></ul></ul><ul><li>Branched-chain amino acids provide most of the energy </li></ul><ul><li>Resistance exercise uses protein less </li></ul><ul><li>Average diet </li></ul><ul><ul><li>Provides ample amount of these amino acids </li></ul></ul><ul><ul><li>Supplements not needed </li></ul></ul>
  22. 22. Fuel Use During Physical Activity
  23. 23. Calorie Needs <ul><li>Individual needs vary </li></ul><ul><li>Monitoring weight and body fat </li></ul><ul><ul><li>If weight falls, increase intake </li></ul></ul><ul><ul><li>If body fat increases, cut back in fat (& kcal) and maintain activity </li></ul></ul><ul><li>Desirable body fat for male athletes: 5%- 18% </li></ul><ul><li>Desirable body fat for female athletes: 17%-28% </li></ul>
  24. 24. Carbohydrate Needs <ul><li>Main fuel for many types of activity </li></ul><ul><li>Consume ~60% of total kcal from carbohydrate </li></ul><ul><li>Adhere to the Food Guide Pyramid </li></ul><ul><li>> 5 gm of carbohydrate/kg body weight </li></ul><ul><li>Aerobic and endurance athletes </li></ul><ul><ul><li>7-10 gm carbohydrates/kg body weight </li></ul></ul><ul><ul><li>~ 500-600 gm of carbohydrates/day </li></ul></ul>
  25. 25. Carbohydrate Loading <ul><li>Events lasting longer than 60-90 minutes </li></ul><ul><li>Maximize glycogen stores </li></ul><ul><li>Tapering of exercise while increasing carbohydrate intake </li></ul><ul><li>Additional water weight </li></ul>
  26. 26. Carbohydrate (CHO) Loading 600 600 600 450 450 450 CHO (grams) rest 20 20 40 40 60 Exercise Time 1 2 3 4 5 6 Days Before Com- petition
  27. 27. Fat Needs <ul><li>~35% of total kcal </li></ul><ul><li>Rich in monounsaturated fats </li></ul><ul><li>Limit saturated fats </li></ul><ul><li>Limit trans fat </li></ul>
  28. 28. Protein Needs <ul><li>Recommend 1.0 - 1.6 gm protein/kg body weight </li></ul><ul><li>Up to 1.7 gm/km body weight for athletes beginning strength training </li></ul><ul><li>Needs are easily met by a normal diet </li></ul><ul><ul><li>Protein supplements are not necessary </li></ul></ul><ul><ul><li>Excessive protein has not been shown to be beneficial </li></ul></ul>
  29. 29. Current Protein Recommendations
  30. 30. Vitamins and Minerals <ul><li>Vitamin E and C </li></ul><ul><ul><li>Slightly higher needs </li></ul></ul><ul><ul><li>Antioxidant properties </li></ul></ul><ul><li>Thiamin, riboflavin, vitamin B-6, potassium, magnesium, iron, zinc, copper, and chromium needs </li></ul><ul><ul><li>May also be higher (role in metabolism or sweat) </li></ul></ul><ul><li>Increase intake of fruits and vegetables </li></ul>
  31. 31. Iron Needs <ul><li>Iron deficiency affects performance </li></ul><ul><li>Sports anemia </li></ul><ul><ul><li>Increase in plasma volume but not RBCs </li></ul></ul><ul><li>Women at risk because of menstruation </li></ul><ul><li>Focus on iron-rich foods </li></ul><ul><li>Use of iron supplement may cause toxic effects </li></ul>
  32. 32. Calcium Needs <ul><li>Restriction of dairy products by women </li></ul><ul><li>Irregular menstruation/Amenorrhea </li></ul><ul><ul><li>Severe bone loss and osteoporosis </li></ul></ul><ul><ul><li>Extra calcium does not compensate for effects of menstrual irregularities </li></ul></ul><ul><ul><li>Compromises bone health </li></ul></ul><ul><li>Calcium deficiency increases risk of stress fractures </li></ul>
  33. 33. Fluid Needs <ul><li>Needs of average adults </li></ul><ul><ul><li>9 cups per day for women </li></ul></ul><ul><ul><li>13 cups per day for men </li></ul></ul><ul><li>Athletes need more </li></ul><ul><li>Maintenance of body ’s cooling system </li></ul><ul><ul><li>Water helps dissipate heat from working muscles </li></ul></ul><ul><li>Avoid losing more than 2% of body weight during exercise </li></ul><ul><li>For every 1lb. lost replace 2.5-3 cups of fluid </li></ul>
  34. 34. Hydration <ul><li>Thirst: Not reliable indicator of fluid needs </li></ul><ul><li>General guidelines: </li></ul><ul><ul><li>Drink 3 C of fluids per each pound of weight loss during activity </li></ul></ul><ul><ul><li>Check urine color </li></ul></ul><ul><ul><li>Drink fluid freely 24 hours before event </li></ul></ul><ul><ul><li>Drink 1 ½ -2 ½ C 2-3 hours before event </li></ul></ul><ul><ul><li>Consume ½ - 1 ½ C every 15 minutes for events lasting longer than 30 min. </li></ul></ul><ul><ul><li>Lose no more than 2% of body weight </li></ul></ul>
  35. 35. Heat Exhaustion <ul><li>Heat stress causes depletion of blood volume due to fluid loss </li></ul><ul><li>Body heat is dissipated through evaporation of sweat (fluid) </li></ul><ul><li>Fluid loss (sweat): ~3-8 C per hour </li></ul><ul><li>Humidity interferes with sweat production </li></ul><ul><li>Dehydration decreases endurance, strength, performance </li></ul><ul><li>Signs: Profuse sweating, headache, dizziness, nausea, weakness, visual disturbances </li></ul>
  36. 36. Heat Cramps <ul><li>Frequent complication of heat exhaustion </li></ul><ul><ul><li>Exercising in heat </li></ul></ul><ul><ul><li>Significant sweating </li></ul></ul><ul><ul><li>Consuming water without sodium </li></ul></ul><ul><li>Painful muscle contractions </li></ul><ul><ul><li>1-3 minutes at a time </li></ul></ul><ul><li>Ensure adequate salt and fluid intake </li></ul><ul><li>Exercise moderately at first in the heat </li></ul>
  37. 37. Heat Stroke <ul><li>High blood flow to working muscles </li></ul><ul><ul><li>Overloads body ’s cooling system </li></ul></ul><ul><ul><li>Sweating ceases </li></ul></ul><ul><ul><li>Internal body temperature reaches 104 ° F </li></ul></ul><ul><ul><li>Fatality rate high </li></ul></ul><ul><li>Symptoms: </li></ul><ul><ul><li>Nausea, confusion, irritability, poor coordination, seizures, coma </li></ul></ul><ul><li>Replace fluids </li></ul><ul><li>Monitor weight change (fluid loss) </li></ul><ul><li>Avoid exercising in hot humid conditions </li></ul>
  38. 38. Sports Drinks For Endurance Exercise <ul><li>Recommended for activity > 60 minutes </li></ul><ul><ul><li>Help maintain blood glucose level and blood volume </li></ul></ul><ul><ul><li>Delay “bonking” </li></ul></ul><ul><li>Supply electrolytes </li></ul><ul><li><60 minutes </li></ul><ul><ul><li>Nutrients are easily replaced by diet </li></ul></ul>
  39. 40. Gels and Bars <ul><li>Provide additional fuel </li></ul><ul><li>Should be taken with fluids </li></ul><ul><li>Expensive source of nutrients </li></ul><ul><li>Ideal bars for endurance athletes </li></ul><ul><ul><li>Contain 40 gm carbohydrate, 10 gm of protein, 4 gram fat, 5 gm of fiber </li></ul></ul><ul><ul><li>Fortified with vitamins and minerals </li></ul></ul><ul><ul><li>Toxicities possible with overuse </li></ul></ul>
  40. 41. Content of Energy Bars and Gels
  41. 42. Hyperhydration <ul><li>Excessive intake of water </li></ul><ul><li>Intake without sodium and chloride </li></ul><ul><li>During prolonged low-intensity activities </li></ul><ul><li>Results in low blood sodium and low blood chloride </li></ul>
  42. 43. Pre-Endurance Event Meal <ul><li>Light meal 2-4 hours prior to event </li></ul><ul><li>Consisting primarily of carbohydrate (top off glycogen stores) </li></ul><ul><li>Low fat (<25% of energy intake) </li></ul><ul><li>Little fiber (prevent bloating, gas) </li></ul><ul><li>Moderate protein </li></ul><ul><li>Avoid fatty, fried foods </li></ul><ul><li>Blended or liquid meal recommended for meals eaten 1-2 hours prior </li></ul>
  43. 44. Recovery Meal <ul><li>Carbohydrate-rich meal within 2 hours after endurance event </li></ul><ul><ul><li>Glycogen synthesis is the greatest </li></ul></ul><ul><ul><li>1-2 gm CHO/kg body weight </li></ul></ul><ul><li>Repeat meal over the next 2 hours </li></ul><ul><li>Choose high glycemic index foods </li></ul><ul><li>Aim for 3:1 carbohydrate-to-protein </li></ul><ul><li>Fluid and electrolyte replacement </li></ul>
  44. 45. Replenishing Muscle Glycogen <ul><li>Availability of adequate carbohydrate </li></ul><ul><li>Ingestion of carbohydrate soon after exercise </li></ul><ul><li>Selection of high-glycemic-load carbohydrate </li></ul><ul><li>Combination of carbohydrate and protein foods </li></ul>
  45. 46. Ergogenic Aids