Prentice6 ppt ch04

Chapter 4: Developing Cardiorespiratory Fitness

McGraw-Hill/Irwin © 2012 McGraw-Hill Companies. All Rights Reserved.

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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

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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

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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

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• 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

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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

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• 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

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– 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

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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

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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

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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

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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

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• 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

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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

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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

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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

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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