Chapter 14 Outline Nutrition and Physical Activity Keys to Good Health 1 Fuel for physical activity a ATP energy carrying molecule in the body i Must be generated continuously since muscles only store enough for 1 3 seconds of activity ii Generated by the breakdown of carbs fats and proteins b After depleting ATP muscles turn to i Creatine phosphate stores some energy that can regenerate ATP 1 Stores enough energy for 3 15 seconds of maximal physical effort 2 Does NOT require oxygen anaerobic c Muscle has 4x as much CP than ATP d After CP glucose is the next source of energy for ATP production i Glucose provides ATP through glycolysis 1 Next fastest mode of production 2 Primary end product pyruvate ii Glucose source during exercise muscle glycogen and blood glucose iii Glycogen stores are limited 1 Used in exercise lasting 30 sec to 3 min iv With limited oxygen pyruvate is converted to lactic acid a byproduct of intense 1 Excess lactic acid goes back into liver to be converted back into glucose activity via the Cori cycle v Glucose metabolism 1 Anaerobic 2 Aerobic breakdown of glucose yields 2 ATP breakdown yields 36 38 ATP a Slower but yield more ATP b Fuels body for 3 min 4 hours c Far fewer acids produced vs anaerobic pathway e Triglycerides fats can be metabolized to generate ATP i For low intensity exercise ii For long duration exercise marathons iii Abundant energy source even for lean people iv 2 x more energy per gram as carbs v Major disadvantage Slowly metabolized vi Primary energy source during rest sitting standing in place and endurance events 2 Sprint start 0 3 sec 100 ATP CP 3 100m Dash 10 12sec 50 ATP CP and 50 carbs 4 1500m race 4 6 min 6 ATP CP and 94 carbs 5 10km race 32 40min 40 fat and 60 carbs 6 Marathon 2 5 3 hours 75 carbs 20 fat 5 other 7 Carbs and Gats can be used for ATP production a Carbs are mostly for high intensity activity b Fats are for low intensity 8 Proteins are NOT used as fuel source for exercise a Only maintenance of blood glucose b 3 6 9 Energy needs a Vigorous exercise increases energy needs and its higher for athletes b Males and females have different energy needs c Depends on body size and type of physical activity d Summary Depends on mode intensity gender size and level of training 10 Carb Needs a Athletes should consume 45 65 carb intake i High or low end depends on sport b Optimize glycogen storage first 4 6 hours of recovery with consistent CHO consumption c Complex less processed carbohydrates whole grains fruits and vegetables supply fiber vitamins and minerals i Evidence suggesting high GI foods for glycogen storage immediately after ii High carb intake within 1st 24hrs is key d Low carb diets are insufficient for optimally restoring muscle glycogen i We need 6 10g CHO kg bw for restoring glycogen 11 Carb glycogen Loading a Consume up to 12g kg bw CHO a day two before event b Alter exercise duration and carbohydrate intake to maximize muscle glycogen c Does not always improve performance i Baseball football weight lifting shorter distance runs d Side effects gastrointestinal distress feeling heavy bloated and sluggish e Experiment to find what works best 12 Training Effect on Fat Metabolism a b Increased number and activity of enzymes involved in fat metabolism Improved ability of muscles to store fat i Intramyocellular lipids content actual increases Improved ability to extract fat from the blood for use during exercise c d Spares carbohydrate for prolonged intense training or competition 13 Protein Needs a Increased protein needs for competitive endurance and resistance athletes i 0 8g kg weight not enough b Those who are already trained need less c Recreational endurance athletes protein need is equal to or slightly higher than the than those who are initiating training protein RDA Inadequate intake is common d Individuals with very low energy intakes i ii Vegetarians consuming low protein foods iii Young athletes who are growing e Competitive endurance and resistance athletes often have greater protein needs f Most non athletes and many athletes already consume more than adequate protein g Claims for a high protein low carbohydrate diet for athletes have not been supported by research h High quality protein sources include poultry fish eggs low fat diary foods legumes i and soy products People of all activity levels can consume more than enough protein by following personalized MyPlate food patterns supplements not necessary 14 Fluid Needs a Functions of water i Lubricant that bathes tissues and cells ii Transportation of nutrients hormones waste products iii Component of chemical reactions hydrolysis iv Part of body tissues proteins and glycogen v Temperature regulation evaporative cooling not in Tallahassee though 15 Water Balance a Heat syncope dizziness b Heat cramps muscle spasms c Heat exhaustion and heatstroke occur on a continuum symptoms include i Excessive sweating weakness nausea dizziness headache difficulty concentrating ii Heatstroke cooling system fails and sweating stops body reaches temperatures 104 F rapid pulse 16 Proper Fluid Replacement a Drink fluids before during and after exercise b Thirst mechanism not reliable i By the time you feel thirsty you re already dehydrated c Drink enough to maintain body weight 17 Vitamins and Minerals 18 Ergogenic Acids a Requirements for some vitamins and minerals may be altered in athletes i B vitamins Calcium and the female athlete triad Iron Iron supplementation may be required under proper medical supervision b c Most nutrient needs can be met with a healthy diet Some have harmful side effects a Substances used to improve exercise and athletic performance b Many are not effective c d Most are expensive e Many have not been adequately studied f Anabolic products are promoted as muscle and strength enhancers include i Anabolic steroids ii Androstenedione andro iii Dehydroepiandrosterone DHEA iv Gamma hydroxybutyric acid GHB v Creatine vi Protein and amino acid supplements i Caffeine ii Ephedrine iii Carnitine iv Chromium v Ribose g Products touted to increase energy levels and optimize fuel use include
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