2. 4-2
Why is cardiorespiratory fitness
important for you?
• Cardiorespiratory endurance is the ability
to perform whole-body activities for an
extended period of time without fatigue
• Some level of cardiorespiratory fitness is
required in order to perform daily activities
• May also greatly reduce the chances of
cardiovascular disease
3. 4-3
What is the difference between
aerobic vs. anaerobic
activities?
• Anaerobic metabolism:
– Kicks in when short bursts of energy are required
– Does not involve the use of oxygen
• Aerobic metabolism:
– Occurs when activity is prolonged
– Involves the use of oxygen
• In most activities both systems function
simultaneously
4. 4-4
How does exercise affect the
function of the heart?
• Cardiovascular
system’s four
components:
– Heart
– Lungs
– Blood vessels
– Blood
• Improvements in
endurance are the
results of improvements
in these 4 components
Figure 4-2
5. 4-5
• As you exercise, the heart must pump
more in order to transport oxygenated
blood to the muscles
• The heart adapts via three
mechanisms:
–Increased heart rate
–Increased stroke volume
–Increased cardiac output
6. 4-6
What determines how efficiently
the body is using oxygen?
• Aerobic capacity/maximum aerobic capacity
– Greatest rate at which oxygen can be taken in
and used during exercise
– Largely, genetically determined range
– More active individuals will tend to have higher
levels and training tends to enhance aerobic
capacity within an individual’s range
7. 4-7
• Range of maximal aerobic capacity,
determined by muscle fiber type
– Fast-twitch fibers
• Fast contracting fibers which are not as dependent
on oxygen and tire rapidly
• Responsible for speed and power
– Slow-twitch fibers
• Slow contracting fibers that are fatigue resistant
and require large amounts of oxygen
• More useful for long duration, endurance activities
8. 4-8
– If you have a greater
percentage of slow
twitch fibers you will
tend to have a higher
aerobic capacity
– Aerobic capacity vs.
workload and relative
percentages of
maximum capacity
Figure 4-3
9. 4-9
How do you know what your
aerobic capacity is?
• Accurate testing is done in the laboratory
setting:
– Involves treadmill running or cycling at a given
intensity while monitoring heart rate and oxygen
consumption
• Impractical for average person
• Heart rate monitoring is an indirect method for
monitoring oxygen uptake
10. 4-10
The FIT Principle
• Basic principles of what is necessary to
gain a training effect from an exercise
program
• FIT:
– Frequency of activity
– Intensity of activity
– Time or duration of activity
11. 4-11
What training techniques can be
used to improve
cardiorespiratory endurance?
• Types of training
– Continuous or sustained training
– Interval training
– Fartlek
• Amount of improvements is largely
determined by initial fitness levels
12. 4-12
Continuous Training
• Exercises performed at the same level of
intensity for long periods of time
• FIT principle should be incorporated to training
• Type: Must be aerobic
• Determining intensity by monitoring heart rate:
– Heart rate can be checked on the thumb side of the
wrist (radial artery), and in the neck (carotid)
– Heart rate monitors can also be utilized to measure
heart rate and effort
13. 4-13
• Target Heart Rate
– Determine maximum heart
rate:
• 220-age = HRmax
• Heart Rate Reserve (HRR)
– Difference between resting
HRrest and HRmax
• Karvonen Equation
– Exercise HR = % of target
intensity(HRmax – HRrest) +
Hrrest
• Rate of Perceived Exertion
(RPE)
Figure 4-5
14. 4-14
Time or duration of activity
• Unfit individuals should engage in no less
than 20 minutes of continuous exercise to
improve cardiorespiratory endurance
• For healthy, fit individuals:
– 30 minutes of moderate intensity activity 5
days a week OR
– 20 minutes of vigorous intensity activity 3
days a week
15. 4-15
Advanced Training Methods
• Interval training
– Alternating periods of intense activity with periods of
active rest
– Allows for more work to be done at more intense
workloads, over a longer period of time
• Fartlek training
– Similar to interval training in the fact activity occurs
over a specific period of time but pace and speed are
not specified
– Consists of varied terrain which incorporates varying
degrees of hills
– Dynamic form of training
16. 4-16
Good Aerobic Activities for
Improving Cardiorespiratory
Endurance• Walking
• Running
• Swimming
• Aerobic exercise
– Floor, step, circuit, water, or
kickboxing
• Cycling
• Spinning
• In-line skating
• Hiking or backpacking
• Rock climbing Figure 4-6
17. 4-17
What is your level of
cardiorespiratory endurance?
• Multiple tests can be done to assess
fitness
– Monitoring of maximum aerobic capacity and
oxygen use
• Maximum aerobic capacity can be
predicted or estimated by measuring heart
rate at varying workloads
