Cardiorespiratory Endurance Chapter Cardiorespiratory Endurance

Cardiorespiratory Endurance Basic Physiology of Cardiorespiratory Endurance Exercise Benefits of Cardiorespiratory Exercise Assessing Cardiorespiratory Fitness Developing a Cardiorespiratory Endurance Program Exercise Safety and Injury Prevention

The Cardiorespiratory System Cardiorespiratory system: system that circulates blood through the body; consists of the heart, blood vessels, and respiratory system

The Cardiorespiratory System The heart Fist-sized muscle with four chambers Pulmonary circulation: circulatory system that moves blood between the heart and the lungs; controlled by the right side of the heart Systemic circulation: circulatory system that moves blood between the heart and the rest of the body; controlled by the left side of the heart

The Cardiorespiratory System The heart Waste-laden, oxygen-poor blood travels through venae cavae, into the heart’s right upper changer, or atrium After the right atrium fills, it contracts and pumps blood into the heart’s right lower chamber, or ventricle Venae cavae: The large veins through which blood is returned to the right atrium of the heart

The Cardiorespiratory System The heart Atrium: The right upper chamber of the heart in which blood collects before passing to the ventricles (pl atria) Ventricle: right lower chamber of heart from which blood flows through arteries to the lungs and other parts of the body Diffusion: process of oxygen moving from lungs to the blood and carbon dioxide moving from blood to the lungs

The Cardiorespiratory System The heart Aorta: The body’s large artery; receives blood from the left ventricle and distributes it to the body Systole: Contraction of the heart Diastole: Relaxation of the heart Blood pressure: The force exerted by the blood on the walls of the blood vessels; created by the pumping action of the heart

FIGURE 3.1 Chambers of the heart

The Cardiorespiratory System Blood vessels Blood vessels classified by size and function Veins: Vessels that carry blood to the heart Arteries: Vessels that carry blood away from the heart

The Cardiorespiratory System Blood vessels Endothelial cells: Cells lining the blood vessels Nitric oxide: A gas released by the endothelial cells to promote blood flow Capillaries: Very small blood vessels that distribute blood to all parts of the body Coronary arteries: Pair of large blood vessels that branch off aorta and supply the heart muscle with oxygenated blood

The Cardiorespiratory System The Respiratory System Respiratory system: The lungs, air passages, and breathing muscles; supplies oxygen to the body and removes carbon dioxide Alveoli: Tiny air sacs in the lungs that allow the exchange of oxygen and carbon dioxide between the lungs and blood

The Cardiorespiratory System The Cardiorespiratory System at rest and during exercise At rest, your heart beats at a rate of about 50 to 90 beats per minute, and you take about 12 to 20 breaths per minute Stroke volume: amount of blood the heart pumps with each beat Cardiac output: amount of blood pumped by the heart each minute; a function of heart rate and stroke volume

Energy Production Metabolic rate: rate at which body uses energy Energy from food Carbohydrates, fats, and proteins Glucose: Simple sugar that circulates in blood and is used by cells to fuel ATP production Glycogen: Complex carbohydrate stored in the liver and skeletal muscles; the major fuel source during most forms of intense exercise Glycogen is the storage form of glucose

Energy Production ATP (adenosine triphosphate): the energy “currency” of cells Adenosine triphosphate (ATP): Energy source for cellular processes Cells store small amount of ATP When they need more, they create it through chemical reactions using body’s stored fuels—glucose, glycogen, and fat

Exercise and the Three Energy Systems Immediate (“explosive”) energy system: Supplies energy to muscle cells through breakdown of cellular stores of ATP and CP

Exercise and the Three Energy Systems Nonoxidative (anaerobic) energy system: Supplies energy to muscle cells through breakdown of muscle stores of glucose and glycogen; also called the anaerobic system or the lactic acid system Anaerobic: Occurring in the absence of oxygen Lactic acid: Metabolic acid resulting from the metabolism of glucose and glycogen

Exercise and the Three Energy Systems Oxidative (aerobic) energy system: Supplies energy to cells through breakdown of glucose, glycogen, and fats; also called the aerobic system Aerobic: Dependent on the presence of oxygen Mitochondria: Cell structures that convert the energy in food to a form the body can use

Exercise and the Three Energy Systems Maximal oxygen consumption (VO2max): Highest rate of oxygen consumption an individual is capable of during maximum physical effort, reflecting the body’s ability to transport and use oxygen; measured in milliliters of oxygen used per minute per kilogram of body weight

Exercise and the Three Energy Systems The energy system in combination Intensity and duration of exercise determines which energy system predominates Physical fitness and energy production Fitness program should target energy system most important to your goals Cardiorespiratory system is the key to overall fitness

Benefits of Cardiorespiratory Endurance Exercise Cardiorespiratory endurance exercise helps the body: Become more efficient Cope better with physical challenges Resist chronic diseases

FIGURE 3.2 Immediate and long-term effects of regular cardiorespiratory endurance exercise

Improved Cardiorespiratory Functioning Endurance exercises enhance heart health: Maintaining or increasing the heart’s blood and oxygen supply Improving the heart muscle’s function Strengthening the heart’s contraction Increasing the heart’s cavity size Increasing blood volume Reducing blood pressure

Improving Cellular Metabolism Regular endurance exercise improves metabolism Increases capillaries in muscles Allows training muscles to make the most of oxygen and fuel Increases mitochondria Prevents glycogen depletion

Reduced Risk of Chronic Disease Cardiovascular Diseases Cancer Type 2 Diabetes Osteoporosis Inflammation Inflammation: body’s response to tissue and cell damage, environmental poisons, or poor metabolic health Deaths from all causes Physically fit people have reduced risk of dying prematurely

Better Control of Body Fat Regular exercise increases daily calorie expenditure Exercise increases resting metabolic rate Improved immune function Immune system: The physiological processes that protect us from diseases such as colds, bacterial infections, and even cancer Exercise increases immune function

FIGURE 3.3 Survival rates for older adults doing vigorous, moderate, or no exercise, 1992–2008 SOURCE: Wen, M, et al 2013 Physical activity and mortality among middle-aged and older adults in the United States Journal Physical Activity & Health Published online

Improved Psychological and Emotional Well-Being Performing physical activities provides proof of skill mastery and self-control Endurance exercises lessen anxiety, depression, stress, anger, and hostility, while improving sleep

Choosing an Assessment Test The 1-Mile Walk Test Estimates level of maximal oxygen consumption based on time it takes to complete one mile of brisk walking and the heart rate at the end of the walk The 3-Minute Step Test Measures how long it takes the pulse to return to normal after three minutes of stepping exercise

Choosing an Assessment Test The 15-Mile Run-Walk Test Oxygen consumption increases with speed The Beep Test A prerecorded series of tones sound off at faster and faster intervals, and the exerciser must keep up with the beeps Monitoring Your Heart Rate Measure your heart rate using a heart rate monitor or counting your pulse beats Interpreting Your Score

FIGURE 3.4 Checking your pulse

Developing a Cardiorespiratory Endurance Program Set realistic goals Set starting frequency, intensity, and duration of exercise at appropriate levels Choose suitable activities Warm up and cool down Adjust program as fitness improves

Setting Goals Set “SMART” goals Specific Measurable Attainable Realistic Time frame-specific

Applying the FITT Equation Frequency of Training Experts recommend 3 to 5 days per week Intensity of Training Target heart rate zone: Heart rates that should be reached and maintained during cardiorespiratory endurance exercise to obtain training effects Heart rate reserve: Difference between maximum heart rate and resting heart rate

Applying the FITT Equation Intensity of training MET: Unit of measure that represents body’s resting metabolic rate Ratings of perceived exertion (RPE): System of monitoring exercise intensity based on assigning a number to the subjective perception of target intensity Talk test

Applying the FITT Equation Time (duration) of training Total duration of 20 to 60 minutes per day recommended Type of activity Cardiorespiratory endurance exercises include activities that involve rhythmic use of large muscle groups for an extended period of time

FIGURE 3.5 Ratings of perceived exertion (RPE) SOURCE: Pick, H L, ed 1978 Psychology from Research to Practice Kluwer Academic/Plenum Publishing Corporation With kind permission of Springer Science and Business Media and the author

TABLE 3.2 Target Heart Rate Zone and 10-Second Counts

TABLE 3.3 Approximate MET and Caloric Costs of Selected Activities for a 154-Pound Person

FIGURE 3.6 The FITT principle for a cardiorespiratory endurance workout

TABLE 3.4 Estimating Exercise Intensity

TABLE 3.5 Sample Progression for an Endurance Program

Warming Up and Cooling Down Warm-up session should include low-intensity, whole body movements similar to those in the activity that will follow Do not use stretching as part of pre-exercise warm-up Cooling down returns the body to a non-exercising state

Building Cardiorespiratory Fitness You must increase the intensity, frequency, and duration of exercise carefully to avoid injury and overtraining Keep an exercise log or training diary Maintaining cardiorespiratory fitness Cross-training: Alternating two or more activities to improve a single component of fitness

Exercise Safety and Prevention Hot weather and heat stress Dehydration: Excessive loss of body fluid Heat cramps: Sudden muscle spasms and pain associated with intense exercise in hot weather Heat exhaustion: Illness resulting from exertion in hot weather Heatstroke: A severe and often fatal heat illness characterized by significantly elevated core body temperature

FIGURE 3.5 Urine chart to assess dehydration SOURCE: Casa, D J, et al April–June 2000 National Athletic Trainers’ Association position statement: Fluid replacement for athletes Journal of Athletic Training 35(2): 212–224, 224a

Exercise Safety and Prevention Cold weather Hypothermia: Low body temperature due to exposure to cold conditions Frostbite: Freezing of body tissues characterized by pallor, numbness, and a loss of cold sensation Wind chill: Measure of how cold it feels based on the rate of heat loss from exposed skin caused by cold and wind Poor air quality

Exercise Injuries Consult a physician for the following: Head and eye injuries Possible ligament injuries Broken bones Internal disorders such as chest pain, fainting, and heat intolerance

Exercise Injuries Managing minor exercise injuries For cuts and scrapes, stop the bleeding and clean the wound For injuries to muscles and joints, use RICE Rest Ice Compression Elevation

Exercise Injuries Preventing injuries Train regularly and stay in condition Gradually increase the intensity, duration, or frequency of workouts Avoid or minimize high-impact activities Get proper rest between exercise sessions Drink plenty of fluids Warm up thoroughly before you exercise and cool down afterward

Exercise Injuries Preventing injuries Achieve and maintain a normal range of motion in your joints Use proper body mechanics Don’t exercise when you are ill or overtrained Use proper equipment Don’t return to your normal exercise program until athletic injuries have healed