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Cardiorespiratory Endurance
© Cengage Learning 2015
© 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 VO2 – 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
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Key Terms
• Adenosine triphosphate (ATP)
– A high-energy chemical compound that the body
uses for immediate energy
• Oxygen uptake (VO2)
– The amount of oxygen the human body uses
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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 (VO2max)
• 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
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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
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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
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Critical Thinking
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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
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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
VO2max through aerobic exercise
© Cengage Learning 2015
Assessment of Cardiorespiratory
Endurance
• Aerobic capacity determined by oxygen uptake
per minute of physical activity (VO2max)
– Higher levels = greater efficiency
– Relative value in mL/kg/min is used most
often
© Cengage Learning 2015
Assessment of Cardiorespiratory
Endurance (cont’d.)
• Components of VO2max
– Heart rate (beats per minute) and maximal
heart rate (MHR)
– Stroke volume (mL per beat)
– Amount of oxygen removed from blood
• (mL of O2 per 100 cc of blood)
• Arterial-venous oxygen difference (a-vO2diff)
© 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.)
• VO2 is computed using the following equation:
VO2 in L/min = (HR x SV x a-vO2diff) ÷ 100,000
– HR = heart rate
– SV = stroke volume
• VO2max is affected by genetics, training, gender,
age, and body composition
• VO2max decreases 1% per year starting at age 25
– 0.5% per year in physically active individuals
© Cengage Learning 2015
Tests to Estimate VO2max
• 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
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1.0-Mile Walk Test
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Step Test
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Astrand–Rhyming Test
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12-Minute Swim Test
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Critical Thinking
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Interpreting the Results
• After obtaining VO2max, you can determine your
current level of CR fitness
• Locate the VO2max in your age category, and find
your present level of CR fitness on the top row
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Cardiorespiratory Fitness Classification
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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?
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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 VO2max
© Cengage Learning 2015
Recommended Cardiorespiratory or Aerobic
Training Pattern
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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
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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
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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 VO2max 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
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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 VO2 of 3.5
mL/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
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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