HUN 1201 STUDGY GUIDE: Chpt 14, 7.5, 8, 9Chapter 14- Nutrition and Physical Activity: Keys to Good HealthFuel for physical activity: ATPCreatine phosphate (CP)GlucosePyruvateGlucose metabolismTriglycerides- ATP • Adenosine triphosphate (ATP): the energy-carrying molecule in the body• ATP must be generated continuously since muscles store only enough ATP for 1–3 seconds of activity• ATP is generated from the breakdown of carbohydrate, fat, and proteinGet energy by breaking phosphate bond- CP • After depleting ATP stores, muscles turn to other sources:– Creatine phosphate (CP) stores some energy that can be used to regenerate ATP– CP stores enough energy for 3−15 seconds of maximal physical effort– Muscle has 4x as much CP than ATP- Glucose • After creatine phosphate, glucose is the next source of energy for ATP production• Glucose provides ATP through glycolysis – Next fastest mode of production• Glucose source during exercise: muscle glycogen and blood glucose• Glycogen stores are limited• Used in exercise lasting 30sec to 3min- Pyruvate • Primary glycolysis end product: pyruvate • With limited oxygen, pyruvate is converted to lactic acid, a by-product of intense activityCori cycle Excess lactic acid goes back to the liver to be converted back into glucose: (gluconeognesis)- Glucose metabolism-Anaerobic-AerobicAnaerobic breakdown of glucose yields 2 ATP moleculesAerobic breakdown of glucose yields 36–38 molecules of ATP- Process much slower but yield is far greater- Fueling the body for 3 min – 4 hours- Far fewer acids produced vs. anaerobic pathway- Triglycerides • Triglycerides (fats) can be metabolized to generate ATP– For low-intensity exercise– For exercise of long duration (think marathons..)– Abundant energy source, even in lean people– 2x more energy per gram as carbohydrates– Slowly metabolized << Major disadvantage– Primary energy source during rest, sitting, and standing inplace; also endurance events Different types of Different fuel sources1HUN 1201 STUDGY GUIDE: Chpt 14, 7.5, 8, 9exercises=High intensity exercise (energy source)CarbohydratesLow intensity exercise (energy source)FatsHow do proteins fit into allthis (energy source)?• Proteins (amino acids) are not used as a fuel source for exercise– Only for maintenance of blood glucose Energy needs dependent on:• Vigorous exercise increases energy needs• Higher for athletes • Different energy needs for males, females• Needs depend on body size• Needs depend on the type of physical activity• So, dependent on: mode, intensity, gender, size, level of training In terms of carbohydrates,athletes need to:• Athletes should consume carbohydrate intakes: 45−65% of total energy– High or low end of range depends on your sport• Optimize glycogen storage: first 4−6 hours of recovery with consistent CHO consumption• Complex, less-processed carbohydrates: whole grains, fruits, and vegetables supply fiber, vitamins, and minerals – Evidence suggesting high GI foods for glycogen storage (immediately after)– High-carb intake within 1st 24hrs is keyCarbohydrate (glycogen) loading:• Consume up to 12g/kg/bw CHO a day/two before event• Alter exercise duration and carbohydrate intake to maximize muscle glycogen• Does not always improve performance– *Baseball, football, weight lifting, shorter-distance runs• Side effects: gastrointestinal distress; feeling heavy, bloated, and sluggishTraining effects on fat metabolism:• Increased number and activity of enzymes involved in fat metabolism• Improved ability of muscles to store fat– Intramyocellular lipids content actual increases• Improved ability to extract fat from the blood for use during exercise • Spares carbohydrate for prolonged, intense training or competitionProtein needs: • Increased protein needs for competitive, endurance, and resistance athletes – 0.8g/kg weight not enough • Those who are already trained need less protein than those who are initiating training• Recreational endurance athletes’ protein need is equal to or slightly higher than the RDA2HUN 1201 STUDGY GUIDE: Chpt 14, 7.5, 8, 9• Inadequate intake is common• Competitive, endurance, and resistance athletes often have greater protein needs• Most non-athletes and many athletes already consume more than adequate proteinFluid needs/ function of water:– Lubricant that bathes tissues and cells– Transportation of nutrients, hormones, waste products– Component of chemical reactions, (hydrolysis)– Part of body tissues (proteins and glycogen)– Temperature regulation: evaporative cooling (not in Tallahassee though!)Heat syncope(symptoms) dizzinessHeat cramps muscle spasmsHeat exhaustion – *Excessive sweating, weakness, nausea, dizziness, headache, difficulty concentrating Heat stoke Cooling system fails and sweating stops, body reaches temperatures ≥ 104°F, rapid pulse!WORST ONEProper fluid replacement • Drink fluids before, during, and after exercise• Thirst mechanism not reliable– By the time you feel thirsty, you’re already dehydrated• Drink enough to maintain body weightVitamins and minerals for athletes/people who exercise:• Requirements for some vitamins and minerals may be altered in athletes– B-vitamins– Calcium and the female athlete triad– Iron• Iron supplementation may be required under proper medical supervision• Most nutrient needs can be met with a healthy dietErgogenic aids • Substances used to improve exercise and athletic performance• Many are not effective • Some have harmful side effects• Most are expensive• Many have not been adequately studied - Anabolic products for muscle and strength enhancers – Anabolic steroids– Androstenedione ("andro")– Dehydroepiandrosterone (DHEA)– Gamma-hydroxybutyric acid (GHB)– Creatine – Protein and amino acid supplementsProducts for increasing energy levels and optimizing fuel:– Caffeine– Ephedrine– Carnitine – Chromium– Ribose3HUN 1201 STUDGY GUIDE: Chpt 14, 7.5, 8, 9Chapter 7.5- Vitamins and MineralsVitamins + minerals vs. MacronutrientsNo energySmaller amount- Function of V + M • Assist body functions – Energy metabolism– Formation and maintenance of healthy cells and tissues Vitamins Contain carbonRegulate a wide range of body processes- Fat soluble • Fat-soluble vitamins: A, D, E, and K – Readily stored in the body’s adipose tissue– Can be toxic
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