Nutri0on and Sports Nutri0on: Ea0ng for Peak Performance BIOL 103, Chapter 11 Exercise is medicine Physical fitness is made up for 5 components: 1. Cardiorespiratory fitness 2. Muscular strength 3. Muscular endurance 4. Body composi<on 5. Flexibility Energy Systems, Muscles, and Physical Performance 1. ATP- CP energy system: Anaerobic: does not require O2 Quick source of ATP Cellular ATP and crea0ne phosphate Fuel for 3 15 seconds of maximal effort Figure 11.1 Develop an Ac<ve Lifestyle To promote health, exercise 30 min/day To achieve and maintain fitness, 29-60 min of con0nuous ac0vity or intermipent aerobic ac0vity, 3-5 days/week 1
Energy Systems, Muscles, and 2. Lac<c acid energy system Accelera0on stage Anaerobic Breakdown of glucose à ATP and Rise in acidity triggers muscle fa0gue How? A rise in acidity à impair breakdown of glucose and inhibits binding à muscles cannot contract Energy Systems, Muscles, and 3. Oxygen energy system Endurance stage Breakdown of carbohydrate and fat for energy in the cell s mitochondria Requires oxygen (Aerobic) Produces ATP more slowly because.? Problem Set 11, Q1 Energy Systems, Muscles, and Name the three types of energy system men0oned in class. Classify them into aerobic and anaerobic. How does each of the system acquire energy? Teamwork in energy produc0on Anaerobic systems Aerobic systems Glycogen deple0on Steady drop of glycogen for first 1.5 hours En0rely depleted at around 3 hours 2
Energy Systems, Muscles, Endurance training Training increases number of mitochondria à improves oxygen delivery à enhances aerobic capacity Decreases reliance on anaerobic systems Extends availability of glycogen Muscles and Muscle Fibers (Problem Set 11, Q2) We have two types of skeletal muscles: Slow- twitch fibers muscles that develop tension more slowly; have high oxida0ve capaci0es low- intensity, long endurance (aerobic endurance) Fast- twitch fibers muscles that can develop high tension rapidly. High- intensity, short endurance Rela0ve propor0on determined by gene0cs Op0mal Nutri0on for Athle0c Performance Figure 11.10 Mix of your Muscle Fibers If you are best at events requiring explosive movements, you may have greater percentage of fast- twitch muscle fibers. If endurance events are your specialty, you may have more slow- twitch fibers. Consume adequate energy and nutri0on (first priority for athletes) 6-10g/kg per day of carbs 1.2-1.7g/kg per day of protein 20-35% of total calories from fat Maintain appropriate body weight and body composi0on Promote op0mal recovery from training Maintain hydra0on status 3
Carbohydrate and Exercise High- carbohydrate diets: Increase glycogen stores Extend endurance Carbohydrate loading 60-70% of calories as carbohydrate Decrease exercise intensity prior to compe00on Not very beneficial if the aerobic ac0vity lasts less than 60-90 minutes. Problem Set 11, Q3a Explain what is carbohydrate loading and why it is beneficial to your running. Carbohydrate intake and Exercise Before exercise Ea0ng carbs 2-4 hours before morning exercise helps replenish glycogen stores and improve endurance Recommend small por0ons and easily digested foods/ beverages During exercise Sports drinks (4-8% carbohydrate + salts/minerals) for events that last at least 1 hour. Aler exercise Replenish glycogen stores: 1-1.5 grams carbohydrate per body kg both 30 minutes and 2 hours aler exercise Dietary Fat and Exercise Fat Major fuel source for endurance (aerobic) ac0vi0es Key point: Endurance training increases the capacity of your oxygen energy system, enhancing your body s ability to use fat as fuel. High- fat diet not needed Recommenda0ons: Moderate fat intake: 20-35% of calories Limits saturated fat to less than 10% of energy Avoid trans fat as much as possible 4
Protein and Exercise Muscles and strength are built with exercise (not extra protein) and carbohydrates provide the fuel needed for muscle- building exercise. Protein recommenda0ons Adults: 0.8 grams per kg body weight Endurance athletes: 1.2-1.7 g/kg Resistance- trained athletes: 1.6-1.7 g/kg Protein sources Foods: lean meats, fish, low- fat dairy, and egg whites Proteins and Exercise Protein intake aler exercise: Protein combined with carbohydrate consump0on aler exercising helps replenish glycogen more efficiently. Dangers of high- protein intake Diuresis (loss of body water) High protein diets are neither recommended nor necessary. Problem Set 11, Q3b Should you s0ll consume dietary fat and protein for your ac0vity? Why or why not? Vitamins, Minerals, and Athle0c Performance 1. B vitamins Needed for energy metabolism 2. Calcium Needed for normal muscle func0on and bones 3. Iron Needed for oxygen delivery and energy produc0on 5
Fluid Needs During Exercise Exercise and fluid loss increase risk for dehydra0on Increased losses from sweat (0.5-2.0 L/hour) Increased with heat, humidity Exercise inhibits thirst signal à you probably won t take in enough fluid if you wait un0l you feel thirsty to replenish your losses. Fluid Needs During Exercise Hydra0on Adequate fluids before, during and aler exercise Should drink fluid at rates that match sweat rates Should you drink water vs. sports drinks? Characteris0cs of Nutri0on Supplements and Ergogenic Aids Ergogenic aids: substances that can enhance athle0c performance Provide calories Provide vitamins and minerals Contribute to performance and enhance recovery Are believed to simulate and maintain muscle growth Nutri0on Supplements and Ergogenic Aids Table 11.10 Types of Ergogenic Aids Nutri0onal, Physiological, Psychological, Biomechanical, Pharmacological Regula0on and concerns about dietary and herbal supplements Bypass FDA safety and effec0veness regula0ons Possibility of product contamina0on 6
Nutri0on Supplements and Ergogenic Aids Weight- gain powders Add an extra 500-1000 calories/day 30-50% weight gain by high calorie diet is muscle, rest is fat No proof that increasing protein intake above recommended levels improves muscle growth Too much protein à extra calories à fat Nutri0on Supplements and Ergogenic Aids and popular theories 1. Crea0ne ATP- CP energy system/aerobic 2. An0oxidants protect muscles/cells from exercise damage 3. Sodium bicarbonate (baking soda) to neutralize lac0c acid 4. Chromium glucose and insulin 5. Iron for anemia 7