CARIDIORESPIRATORY ENDURANCE Chapter 4
Test your knowledge • Compared to sedentary people, those who engage in regular moderate endurance exercise are likely to • Have fewer colds • Be less anxious and depressed • Fall asleep more quickly and sleep better. • Be ore alert and creative. • ALL FOUR. Endurance exercise has many immediate benefits that affect all the dimensions of wellness and improve overall quality of life.
Test your knowledge • About how much blood does the heart pump each minute during aerobic exercise? • 5 quarts • 10 quarts • 20 quarts • 20 QUARTS. During exercise, cardiac output increases to 20 or more quarts per minute, compared to about 5 quarts per minute at rest.
Test your knowledge • During an effective 30 minute cardio respiratory endurance workout, you should lose 1 – 2 pounds. True or False? • FALSE. Any weight loss during an exercise session is due to fluid loss that needs to be replaced to prevent dehydration and enhance performance.
Basic physiology • The Cardio – Respiratory System • Consists of: • Circulatory system • Heart • Blood vessels • Respiratory system
The heart • Pulmonary circulation • Right side • Pumps blood to the lungs • Systemic circulation • Left side • Pumps blood to the body
The heart beat • Systole • Heart’s contraction • Blood flows out of the heart • Diastole • Hearts relaxation • Blood flows into the heart • Blood pressure • Force exerted by blood on the walls of the blood vessels • Created by the pumping action of the heart • Heart beat: • Nerve impulses • Pacemaker – sinoatrial node (SA)
Blood vessels • Veins • Carry blood towards the heart • Thin walls • Valves • Arteries • Carry blood away from the heart • Thick, elastic walls • Capillaries • Smallest blood vessels • 1 cell thick
Heart’s blood vessels • The heart has its own network of arteries, veins and capillaries. • Coronary arteries (2) • Branch off the aorta • Supply the heart muscle with oxygenated blood
Respiratory system FUNCTION HOW IT WORKS Supplies oxygen to the body Carries off carbon dioxide Helps to regulate acid produced during metabolism. Lungs expand and contract by the contraction and relaxation of the diaphragm and rib cage Alveoli are the site of gas exchange.
The cardio-respiratory system at rest and during exercise At rest During exercise Heart beats 50 – 90 per min. Breaths 12 – 20 per min. Blood pressure 120 systolic, 80 diastolic (120/80) Blood flow 15 – 20% directed to skeletal muscles. Cardiac output of 5 quarts per minute. Heart beats 170 – 210 per min Breaths 40 – 60 per min. Blood pressure 175 systolic, 65 diastolic (175/65) Blood flow 85 – 90% directed to skeletal muscles. Cardiac output increases to 20 or more quarts per minute. Stroke volume increases More blood per minute
Energy Production Metabolic rate • Metabolism is the sum of all the chemical – physical changes that take place within the body that enable it to grow and function. • At rest low • During movement increases • 800% during intense exercise • Olympic caliber distance runners – 2000%
Energy Production • Energy from food • Comes from carbohydrates, fats and protein • During digestion are broken down to glucose • Some glucose remains in blood as a quick source of fuel to produce energy • The rest of it is converted to glycogen and stored in the liver, muscles and kidneys. • The remaining glucose is converted to fat and stored in fatty tissues.
Energy Production • ATP adenosine triphosphate • Basic form of energy used by cells • Released by a series of chemical reactions from stored fuels (glucose, glycogen and fat)
Exercise and the three energy systems The immediate energy system The non-oxidative energy system (anaerobic respiration) The oxidative energy system (aerobic respiration)
Exercise and the three energy systems • The immediate energy system • Provides energy rapidly, only in a short period of time(10 or less seconds) • Energy comes from existing cellular ATP stores and creatine phosphate (CP), a chemical used to produce more ATP.
Exercise and the three energy systems • The non-oxidative energy system (anaerobic respiration) • Used at the start of an exercise • For high intensity activities • Lasts from 10 seconds to 2 minutes • Creates ATP by breaking down glucose and glycogen in the absence of Oxygen. LIMITATIONS • Its supply of glucose and glycogen are limited • Releases hydrogen ions that are thought to interfere with metabolism and muscle contraction causing fatigue. • Also creates metabolic acids (lactic acid)
Exercise and the three energy systems • The oxidative energy system (aerobic respiration) • Used during any physical activity that lasts longer than about 2 minutes • Requires O2 to generate ATP • It is not an immediate source of energy, but lasts longer. • Takes place in the mitochondria • The body stores of fuel for this system are much greater. • At high intensity exercise burns carbs, and at low intensity exercise burns fats. LIMITATIONS • Glycogen depletion • Supply of Oxygen (VO2max, Max. O2 consumption)
0 sec 4 sec 10 sec 1.5 min 3 min + Strength – Power:power lift, shot put, golf swing Sustained Power:sprints, fast breaks, football Anaerobic Power – Endurance:200-400 m dash, 100 m swim Aerobic Power : hiking, distance running, swimming Immediate/short-term Aerobic-oxidativenon-oxidative systems system
Energy systems in combination • Your body uses all three energy systems when you exercise
Think… • What type of physical activities involve… • The immediate energy system? • Weight lifting • Rising from a chair • Picking up a heavy package. • The non-oxidative energy system? • 400 m run • Climbing stairs • Running behind a bus • The oxidative energy system? • Distance running • Swimming • Hiking • Standing in line
Benefits of cardio respiratory endurance • Improved cardio respiratory functioning • Maintains or increases the heart’s own blood and oxygen supply • Increases heart muscle’s function. • Strengthening hearts contractions • Increases heart’s cavity size • Increases blood volume • Reduces blood pressure. • Improved cellular metabolism • Increases the number of capillaries in the muscles • Trains muscles to work efficiently: get the most out of O2 and fuel. • Increases the size and number of mitochondria in muscle cells • Prevents glycogen depletion and increases the ability of muscles to use lactic acid and fat as fuels. • Protects cells from damage produced by free radicals.
Benefits of cardio respiratory endurance • Reduced risk of chronic disease • Cardiovascular diseases • Healthy balance in blood levels of glucose and cholesterol • Reduces blood pressure • Betters the function of cells that line arteries • Reduces inflammation • Prevents obesity • Cancer • Studies show a relationship between increased physical activity and a reduction in a person’s risk of cancer. • Type 2 diabetes • Exercise burns sugars and makes cells more sensitive to the hormone insulin • Osteoporosis • Helps build bone and muscles • Death from all causes • Poor fitness is a good predictor of premature death.
Benefits of cardio respiratory endurance • Better control of body fat • Regular exercise boosts your calorie expenditure (metabolism) • Improved immune function • Moderate endurance exercise boosts your immune function • Overtraining depresses it. • Influences the levels of specialized cells and chemicals involved in the immune response. • Improved psychological and emotional well being • Improves your self image. • Opportunities to socialize • Lessens anxiety, depression, stress, anger and hostility • Improves sleep
Assessing Cardio respiratory Endurance • Assessment tests • 1-mile walk test • Amount of time it takes you to complete 1 mile of brisk walking and your heart rate at the end of your walk • 3-minute step test • Rate at which the pulse returns to normal after exercise • 1.5 mile run-walk test • Indicates high maximal oxygen consumption (VO2max)
Assessing Cardio respiratory Endurance Monitoring your heart rate sphygmomanometer
LAB 4.1. • Use the 3-minute step test to assess your level of cardio respiratory endurance • http://webmetronome.com/
Developing a Cardio respiratory Endurance ProgramTo develop a successful endurance program, you should… • Set realistic goals • Improve your maximal oxygen consumption (VO2max) • Improve your resting heart rate. • Become more energetic, sleep better, fit on clothes.
Set your starting frequency, intensity and duration of exercise at appropriate levels and choose suitable activities (FITT) • Frequency: 3 – 5 days per week depending on the intensity of the activity • Time: a total duration of 20 – 60 minutes is recommended on a single session or multiple 10 min sessions. • Type of activity: consider your preferences, access to facilities, equipment, time required for a proper workout
Intensity: intensely enough to stress your body • Target heart rate zone: rate at which you should exercise to experience cardiorespiratory benefits (65% to 90% of your maximum heart rate) • Estimate your maximum heart rate by subtracting your age from 220 • Multiply your MHR by 65% and 90% • Heart rate reserve: difference between maximum heart rate and resting heart rate • The target heart rate is equal to resting heart rate plus between 50% and 85% of heart rate reserve
Intensity: intensely enough to stress your body • Monitor your heart rate • Count your pulse while you’re still moving or immediately after you stop • Count beats for 10 seconds and multiply that number by 6 • METS: represent a measure of the metabolic cost of exercise • One MET represents the body’s resting metabolic rate • 6-8 METs are moderate-intensity exercises • More than 10 METs are vigorous exercise
Intensity: intensely enough to stress your body • Ratings of Perceived Exertion: • Scale of ratings to monitor the intensity of your exercise session without checking your pulse. (Fig 4.6) • Talk Test • Although your breathing rate will increase during exercise, you should not work out so intensely that you cannot speak comfortably.
LAB 4.2 Developing an Exercise Program for Cardio-respiratory Endurance. Calculate your target heart rate
Warming up and cooling down • Warm up before every session • Enhances performance • Decreases the chance of injury • Gives the body time to redirect blood to active muscles • The heart adapts to increased demands • Helps to spread synovial fluid throughout the joints. • Cool down afterwards • Stretching is a good option • Helps to maintain blood flow to the heart and brain • Redirects blood from working areas of the body • Helps to prevent a large drop in blood pressure
Exercise Safety and Injury Prevention • Hot weather and heat stress • Dehydration • Increases body temperature and decreases sweat rate, exercise capacity, muscular strength and many body functions. • Heat cramps • Depletion of sodium and potassium from the muscles is involved • Primary cause is muscular fatigue. • Heat Exhaustion • Produces a rapid weak pulse, low blood pressure, headache, faintness, weakness, dizziness, profuse sweating, pale face, psychological disorientation and slightly elevated body temperature. • Heat stroke • Is a failure of the brain’s temperature regulatory center, the body does not sweat enough, body temperature rises to extremely dangerous levels.
Exercise Safety and Injury Prevention • Cold weather • Hypothermia • Depresses the central nervous system • Sleepiness • Lower metabolic rate • Body temperature declines • Coma, death. • Frostbite • Freezing of body tissues (earlobes, fingers, toes) • Can cause permanent circulatory damage
Exercise Safety and Injury Prevention • Poor air quality • Air pollution can decrease exercise performance and negatively affect health • It could decrease lung function as much as smoking • Symptoms include eye and through irritations, difficulty to breath, headache and malaise.
Exercise Safety and Injury Prevention • Exercise Injuries • When to call a physician • Head and eye injuries • Possible ligament injuries • Broken bones • Internal disorders: chest pain, fainting, elevated body temperature, intolerance to hot weather. • Minor injuries: can be treated with the R.I.C.E. principle • Rest • Ice • Compression • Elevation
Exercise Safety and Injury Prevention • Exercise Injuries • Preventing injuries • Train regularly and stay in condition • Gradually increase the intensity, duration or frequency of your workout • Avoid high – impact activities • Get proper rest between exercise sessions • Drink plenty of fluids • Warm up and cool down • Maintain a good level of flexibility • Us proper body mechanisms for lifting objects or executing sports skills • Don’t exercise when you are ill or over trained • Use proper equipment • Don’t return to your normal exercise program until any athletic injuries have been healed.