Transcript Slide 1

Chapter 3 Lecture
Cardiorespiratory
Endurance:
Assessment and
Prescription
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Learning Objectives
• Explain the benefits of developing cardiorespiratory
endurance
• Identify the two energy systems used in ATP production
for muscular contraction
• Discuss the role of the circulatory and respiratory
systems during exercise
• Define VO2max
• Identify the main changes that occur in the skeletal,
circulatory, and respiratory systems in aerobic training
• List several modes of cardiorespiratory training
• Outline the main components of an exercise prescription
for cardiorespiratory fitness
• Design a cardiorespiratory endurance exercise program
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What Is Cardiorespiratory Endurance
and What Does It Do?
• The ability to perform aerobic exercises for a
prolonged period of time
• Promotes weight loss
• Reduces risk of cardiovascular disease (CVD)
• Widely considered to be the most important
component of health-related physical fitness
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What Is the Cardiorespiratory System?
• It is made up of the following two cooperating
systems:
– the cardiovascular/circulatory (the heart and
blood vessels) system
– the respiratory (the lungs and related
muscles) system
• Together, these systems deliver oxygen and
nutrients, and remove waste products,
throughout the body
• Exercise challenges the cardiorespiratory
system by increasing the demand for oxygen
and nutrients in working muscles
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The Role of VO2max
• The most valid measure of cardiorespiratory
fitness
• VO2max = maximal aerobic capacity (the
maximum amount of oxygen the body can take
in and use during exercise)
• VO2max measures the endurance of the
cardiorespiratory system and the skeletal
muscles during exercise
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The Cardiovascular System
The Heart (two pumps in one)
• Right side/pulmonary circuit
• Left side/systemic circuit
Blood Vessels
• Arteries: carry blood away from the heart
• Veins: carry blood from body tissues back to
the heart
• Capillaries: thin-walled blood vessels that
allow oxygen and nutrients to pass through to
tissues, and waste products (e.g.,carbon
dioxide) to pass back into the vascular system
for processing
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The Respiratory System
• Controls breathing
• Consists of lungs and related muscles
• The lungs
– exhale carbon dioxide and waste products
– inhale oxygen, some of which passes into
alveoli (tiny air sacs), and then into capillaries
– send oxygen-rich blood back to the heart
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Blood Flow Through the Cardiorespiratory
System
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Getting Energy for Exercise
• Energy
– The fuel needed for muscle motion
– Derived from the breakdown of food
• Energy released from the breakdown of food creates a
compound called ATP (adenosine triphosphate)
• ATP is stored in muscle and cells in small amounts
• The breakdown of ATP creates energy in a form that
muscles can use for movement
• Therefore, ATP must be available for muscles in order for
them to function
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Aerobic and Anaerobic Systems
Two systems in muscle cells produce ATP
• Anaerobic (without oxygen)
– Provides energy for exercise that is short duration and
intense, at the beginning of activity
– Produced through glycolysis, a process that breaks down
carbohydrates
– Can only use carbohydrates as an energy source
• Aerobic (with oxygen)
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The primary system for cardiorespiratory endurance
Relies on oxygen for ATP production
Can use fats, proteins, and carbohydrates to produce ATP
Supports prolonged exercise, with a shift from carbohydrates
to fats as the primary energy source
– Most daily activities rely on aerobic ATP production
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Energy Metabolism During Exercise
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Changes in the Cardiorespiratory System
from Exercise and Training
Responses to exercise
• Short-term changes that occur during and
immediately after exercise
Adaptations to exercise
• Changes over time that accrue with regular
exercise
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Responses to Exercise
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Heart rate increases
Stroke volume increases
Arteries dilate/expand
Breathing rate increases
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Adaptations to Exercise
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Resting heart rate decreases
Maximum stroke volume increases
VO2max increases
Respiratory muscle endurance improves
Muscles' capacity to produce aerobic energy
increases
• Adaptations are lost/reversed if exercise is
stopped for an extended period
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Relationship Between Training Intensity
and VO2max Improvement
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Health Benefits of Cardiorespiratory
Endurance
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Lower risk of heart disease
Reduced risk of type 2 diabetes
Lower blood pressure
Increased bone density
Increased energy
Improved well-being and self-esteem
Easier weight control
Better sleep
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Evaluating Cardiorespiratory Endurance
1.5-mile run test
• One of the simplest and most accurate tests
1-mile walk test
• Widely used field measure
Cycle ergometer test
• Non-weight-bearing/good for people with joint
problems
Step test
• Can be performed by people at any fitness
level
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Designing Your Aerobic Exercise Program
• Set goals (short-term and long-term)
• Warm-up
• Workout (FITT principle)
– Frequency (e.g., 3–5 times per week)
– Intensity (e.g., 50–85% of maximal heart rate)
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training threshold
target heart rate (THR)
heart rate reserve (HRR)
Borg Rating of Perceived Exertion (RPE)
– Time/duration (e.g., 20–60 minutes per session)
– Type/mode of exercise (e.g., jogging)
• Cool-down
• Main stages of the exercise program: initial conditioning,
progression, and maintenance
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Calculate Target Heart Rate (THR)
• Maximal HR
– HRmax = 206.9 – (.67 x age yrs.)
• 206.9 – (.67 x 20 yrs.) = HRmax of 194bpm
– HRR (heart rate reserve) = HRmax – Resting
HR
• 194 HRmax – 60RHR = HRR of 134bpm
– Calculate 50% to 85% of HRR and add RHR
to obtain THR
• .50 x 134HRR = 67bpm + 60RHR = THR of 127bpm
• .85 x 134HRR = 114bpm + 60RHR = THR of 174bpm
– THR range of 127bpm to 174bpm for 20 yr. old
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Sample Workout in the Target Heart Rate
Range
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Maximal Heart Rate Over Time
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Borg Rating of Perceived Exertion (RPE)
• Consider overall
– Breathing rate
– Amount of sweating
– Muscle fatigue
• 15-point scale, ranging from 6 to 20
– 6 on the scale means that there is no level of
exertion
– 8–11 on the scale is common during the
warm-up or cool-down phase of the workout
– 12–16 on the scale will correspond with the
target heart rate range for most people
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Exercises and Activities That Can
Improve Cardiorespiratory Fitness
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Developing an Individualized Exercise
Prescription
Initial Conditioning Phase
• Lasts roughly 2–4 weeks
• Start at a comfortable intensity level
• Increase duration or intensity gradually
(separately not both at once)
• Be aware of body pains, and rest as needed
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Developing an Individualized Exercise
Prescription (cont.)
Improvement Phase
• Ranges from 12 to 40 weeks
• Progress is more rapid than in initial phase
• Increase duration and frequency first, then
intensity
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Developing an Individualized Exercise
Prescription (cont.)
Maintenance Phase
• Fitness goal has been achieved
• Continue exercising regularly, but no need to
continue increasing duration, frequency, and
intensity
• Key factor in maintenance appears to be
intensity level
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Training Techniques
Endurance training techniques = continuous
activity at a constant intensity level
Cross Training
• Alternate multiple training modes
• May reduce risk of overuse injuries
• Improves overall cardiorespiratory endurance
• Some people enjoy increased variety
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Training Techniques (cont.)
Interval Training
• Often used by athletes to attain higher
endurance levels in specific fitness areas
• Uses repeated sessions (intervals) of higherintensity exercises alternated with lowerintensity exercises
• May be used to spur gains in intensity during
improvement phase
• Should not be done on a daily basis
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Staying Motivated
• Most common reason cited for dropping out of exercise
programs is lack of time
• Recognize that making time for exercise can be
challenging, but not impossible
• Schedule a regular time to exercise and stick with it
• Remember that small time investments in exercise can
lead to big improvements: in your total available hours
per week, as few as three 30-minute workouts (workout
phase) can improve cardiorespiratory health
• Create goals and seek support
• Keep a record of your progress
• Don't get discouraged by initial aches or pains; they will
improve as you continue to exercise
• You will feel, look, and function better in all areas of your
life
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Summary
• Cardiorespiratory fitness benefits include lower disease
risk, greater capacity for everyday tasks, and improved
self-esteem
• ATP provides the energy muscles need to move: It is
produced by the anaerobic (without oxygen) and aerobic
(with oxygen) systems
• Anaerobic ATP is the primary energy source for shortterm exercise; aerobic ATP production fuels prolonged
exercise
• The cardiorespiratory system is two cooperating
systems: 1) the cardiovascular/circulatory and 2) the
respiratory. The circulatory system transports blood
carrying oxygen and nutrients to body tissues. The
respiratory system loads oxygen into and removes
carbon dioxide from the blood.
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Summary (cont.)
• Responses are short-term bodily changes that
meet the immediate demands of exercising;
adaptations are long-term changes that result
from regular training, and remain as long as
training continues.
• VO2max measures the maximum capacity of the
cardiorespiratory system to transport and use
oxygen during exercise. Different field tests can
estimate VO2max.
• The main elements of an exercise prescription
are warm-up, workout, and cool-down
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Summary (cont.)
• The components of the workout phase are
frequency, intensity, time/duration, and
type/mode of exercise (FITT)
• An exercise prescription for improving
cardiorespiratory fitness has three phases: initial
conditioning, improvement, and maintenance
• Maintaining a successful exercise program
requires managing your time and selecting
activities you enjoy
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