6 Cardiorespiratory Endurance Cengage Learning 2015 Cardiorespiratory Endurance

6 Cardiorespiratory Endurance © Cengage Learning 2015

Cardiorespiratory Endurance • Cardiorespiratory endurance – Ability of lungs, heart, and blood vessels to deliver enough oxygen to cells to meet demands of prolonged physical activity – The most important part of health-related physical fitness • Lack of physical activity leads to hypokinetic diseases such as hypertension, heart disease, chronic low back pain, and obesity – Aerobic exercise is especially important in preventing cardiovascular disease © Cengage Learning 2015

Basic Cardiorespiratory Physiology • CR endurance measures how pulmonary, cardiovascular, and muscular systems work together during aerobic activities – Oxygen taken up by alveoli in the lungs and transported in blood hemoglobin, and then through the circulatory system – Oxygen converts food into ATP through aerobic metabolism – Oxygen uptake, or VO 2 – indicates more efficient CR system © Cengage Learning 2015

Key Terms • Alveoli – Air sacs in the lungs where oxygen is taken up and carbon dioxide (produced by the body) is released from the blood • Hemoglobin – Iron-containing compound, found in red blood cells, that transports oxygen © Cengage Learning 2015

Key Terms • Adenosine triphosphate (ATP) – A high-energy chemical compound that the body uses for immediate energy • Oxygen uptake (VO 2) – The amount of oxygen the human body uses © Cengage Learning 2015

Aerobic and Anaerobic Exercise • Cardiorespiratory endurance activities are called aerobic exercises – Requires oxygen to produce energy (ATP) to carry out the activity – Examples: walking, jogging, swimming • Anaerobic exercise is so intense that oxygen can’t be delivered and used to produce energy – Does not require oxygen to produce the necessary energy (ATP) to carry out the activity. © Cengage Learning 2015

Benefits of Aerobic Training • • Higher maximal oxygen uptake (VO 2 max) Increase in oxygen-carrying capacity of blood Decrease in resting heart rate (RHR) Increase in cardiac output and stroke volume – Cardiac output: amount of blood pumped by the heart in one minute – Stroke volume: amount of blood pumped by the heart in one beat © Cengage Learning 2015

Benefits of Aerobic Training (cont’d. ) • Beneficial physiological adaptations (cont’d. ) – Lower heart rate at given workloads • Load placed on body during physical activity – Increase in number, size, and capacity of mitochondria • Structures within cells where energy transformations take place – Increase in number of functional capillaries • Smallest blood vessels carrying oxygenated blood to the body © Cengage Learning 2015

Benefits of Aerobic Training (cont’d. ) • Beneficial physiological adaptations (cont’d. ) – Faster recovery time after exercising • Time the body takes to return to resting levels after exercise – Lower blood pressure and blood lipids – Increase in fat-burning enzymes © Cengage Learning 2015

Critical Thinking © Cengage Learning 2015

Physical Fitness Assessment • Assessment serves several purposes: – Educate participants about current fitness levels – Motivate individuals – Provide starting point – Evaluate improvements in fitness – Monitor changes throughout the years © Cengage Learning 2015

Responders versus Nonresponders • Principle of individuality: genetics play a role in response to exercise • Responders readily show improvements • Nonresponders exhibit small or no improvements at all – A lower-body strength-training program has been shown to help nonresponders improve VO 2 max through aerobic exercise © Cengage Learning 2015

Assessment of Cardiorespiratory Endurance • Aerobic capacity determined by oxygen uptake per minute of physical activity (VO 2 max) – Higher levels = greater efficiency – Relative value in m. L/kg/min is used most often © Cengage Learning 2015

Assessment of Cardiorespiratory Endurance (cont’d. ) • Components of VO 2 max – Heart rate (beats per minute) and maximal heart rate (MHR) – Stroke volume (m. L per beat) – Amount of oxygen removed from blood • (m. L of O 2 per 100 cc of blood) • Arterial-venous oxygen difference (a-v. O 2 diff) © Cengage Learning 2015

Key Terms • Maximal heart rate (MHR) – Highest heart rate for a person, related primarily to age • Arterial-venous oxygen difference – Amount of oxygen removed from the blood as determined by the difference in oxygen content between arterial and venous blood © Cengage Learning 2015

Assessment of Cardiorespiratory Endurance (cont’d. ) • VO 2 is computed using the following equation: VO 2 in L/min = (HR x SV x a-v. O 2 diff) ÷ 100, 000 – HR = heart rate – SV = stroke volume • VO 2 max is affected by genetics, training, gender, age, and body composition • VO 2 max decreases 1% per year starting at age 25 – 0. 5% per year in physically active individuals © Cengage Learning 2015

Tests to Estimate VO 2 max • Five tests used to assess CR fitness: – 1. 5 -Mile Run Test – 1. 0 -Mile Walk Test • For those unable to run; heart rate of at least 120 bpm – Step Test – Astrand-Rhyming Test – 12 -Minute Swim Test © Cengage Learning 2015

1. 5 -Mile Run Test © Cengage Learning 2015

1. 0 -Mile Walk Test © Cengage Learning 2015

Step Test © Cengage Learning 2015

Astrand–Rhyming Test © Cengage Learning 2015

12 -Minute Swim Test © Cengage Learning 2015

Critical Thinking © Cengage Learning 2015

Interpreting the Results • After obtaining VO 2 max, you can determine your current level of CR fitness • Locate the VO 2 max in your age category, and find your present level of CR fitness on the top row © Cengage Learning 2015

Cardiorespiratory Fitness Classification © Cengage Learning 2015

Principles of CR Exercise Prescription • Adherence to exercise is enhanced if you are able to make it through 4 to 6 weeks of training • The first step is to ask yourself: Am I ready to start an exercise program? © Cengage Learning 2015

Guidelines for CR Exercise Prescription • To develop the CR system, the heart muscle has to be overloaded • FITT-VP – Frequency – Intensity – Time (duration) – Type (mode) – Volume – Progression © Cengage Learning 2015

Intensity of Exercise • Cardiorespiratory stimulation: make heart pump faster for a specified time period • Health and fitness benefits – 30 to 85% of heart rate reserve (HRR) – Appropriate duration and frequency © Cengage Learning 2015

Intensity of Exercise (cont’d. ) • Determine the intensity of exercise or cardiorespiratory training zone: – MHR = 207 – (. 7 x age) – HRR = MHR – RHR – Calculate TIs at 30, 40, 50, 60, 70, 85% – % TI = [HRR x (%)] + RHR © Cengage Learning 2015

Key Terms • FITT-VP – Frequency, intensity, type, time, volume, progression • Vigorous exercise – High intensity level (>70% max) • Moderate exercise – Noticeably increases heart rate and breathing © Cengage Learning 2015

Key Terms • Heart rate reserve (HRR) – Maximal minus resting heart rate • Cardiorespiratory training zone – Recommended training intensity range to obtain adequate cardiorespiratory endurance development © Cengage Learning 2015

Moderate- vs. Vigorous-Intensity Exercise • As intensity increases, adherence decreases, and injuries increase • Moderate-intensity physical activity (about 50 percent TI) provides many health benefits, including decreased risk for cardiovascular mortality • Vigorous-intensity programs yield higher improvements in VO 2 max © Cengage Learning 2015

Recommended Cardiorespiratory or Aerobic Training Pattern © Cengage Learning 2015

Monitoring Exercise Heart Rate • Count your pulse for 10 seconds, then multiply by six to get the per minute pulse rate • Monitor regularly in beginning of program – Make sure you are in the proper zone • Assess activity level based on pulse rate – Consider personal fitness goals © Cengage Learning 2015

Rate of Perceived Exertion (RPE) • Rate of perceived exertion (RPE) – A perception scale to monitor or interpret the intensity of aerobic exercise • Alternative to checking pulse – Rate of exercise difficulty • Cross-check with target zone – Reexamine periodically © Cengage Learning 2015

Perceived Exertion Scale © Cengage Learning 2015

Mode of Exercise • The mode, or type, of exercise that develops the CR system has to be aerobic in nature • Involves major muscle groups • Choose activities based on personal preferences © Cengage Learning 2015

Mode of Exercise (cont’d. ) • Optimal health benefits – Lower end of cardiorespiratory zone • Greater improvements – Higher end of cardiorespiratory zone • Specificity of training – Use same mode for exercise as testing © Cengage Learning 2015

Duration of Exercise • Exercise between 20 to 60 minutes per session • Up to 90 minutes daily may be required to prevent weight gain • Even accumulation of 30 min moderate activity, conducted for at least 10 minutes three times per day, benefits the CR system • 5 hours of moderate activity, or 2. 5 hours of vigorous activity per week provide additional benefits © Cengage Learning 2015

Duration of Exercise (cont’d. ) • Novice and overweight exercisers need proper conditioning prior to vigorous exercise to avoid injuries or cardiovascular-related problems • Exercise sessions always should be preceded by a 5 - to 10 -minute warm-up and be followed by a 10 -minute cool-down period • A warm-up consists of general exercises at a lower intensity than the actual target zone © Cengage Learning 2015

Frequency of Exercise • Recommended exercise frequency for aerobic exercise is 3 to 5 days per week • Three 20 - to 30 -minute exercise sessions per week, on nonconsecutive days, are sufficient to improve (in the early stages) • Endurance athletes may train at or above the anaerobic threshold © Cengage Learning 2015

Key Terms • Anaerobic threshold – The highest percentage of the VO 2 max at which an individual can exercise (maximal steady state) for an extended time without accumulating significant amounts of lactic acid • Volume of exercise – The product of frequency, intensity, and duration – Minimum volume of 1000 calories per week recommended © Cengage Learning 2015

Excessive Sitting: A Deadly Proposition • People who sit most of the day have up to a 50% greater risk of dying prematurely and an 80% greater risk of cardiovascular disease • Ways to enhance daily nonexercise activity thermogenesis (NEAT) – Stand as much as possible; use a standing or a treadmill desk; use a stability ball for a chair; hold “walking” meetings; walk to co-workers’ offices instead of phoning; take intermittent breaks; park farther away; take the stairs © Cengage Learning 2015

Rate of Progression • Rate of progression depends on health status, exercise tolerance, and program goals – Initially, only three weekly training sessions of 15 to 20 minutes are recommended to avoid musculoskeletal injuries – Increase duration by 5 -10 minutes per week and frequency up to 5 times per week by the fourth or fifth week – Progressively increase frequency, duration, and intensity of exercise until you reach your fitness maintenance goal © Cengage Learning 2015

Physical Activity Pyramid © Cengage Learning 2015

Fitness Benefits of Aerobic Activities • Effort determines benefits and physiological development • Beginners should start with light-intensity activities that carry a minimum risk for injuries • METs (metabolic equivalents) measure intensity of exercise in multiples of resting metabolic rate – 1 MET is the equivalent of a VO 2 of 3. 5 m. L/kg/min – MET levels for a given activity vary according to the effort expended © Cengage Learning 2015

Getting Started • The first few weeks are the most difficult • Reduce muscle soreness, stiffness, and risk for injuries by gradually increasing exercise intensity, duration, and frequency • Once you begin to see positive changes, it won’t be as hard © Cengage Learning 2015

A Lifetime Commitment to Fitness • Benefits are maintained through a regular lifetime program • Four weeks of aerobic training are completely reversed in two weeks of physical inactivity • Staying with a physical fitness program long enough brings about positive physiological and psychological changes © Cengage Learning 2015

Assess Yourself • Do you consciously attempt to incorporate as much physical activity as possible in your daily living? • Do you understand the following concepts? – Cardiorespiratory endurance training – Aerobic and anaerobic exercise – Assessing cardiorespiratory fitness • 1. 5 -mile run test, 1. 0 -mile walk test, step test, Astrand-Rhyming test, 12 -minute swim test © Cengage Learning 2015