Cardiorespiratory Endurance

advertisement
CARIDIORESPIRATORY
ENDURANCE
CHAPTER 4
Test your knowledge
 Compared to sedentary people, those who engage in
regular moderate endurance exercise are likely to




Have fewer colds
Be less anxious and depressed
Fall asleep more quickly and sleep better.
Be ore alert and creative.

ALL FOUR. Endurance exercise has many immediate benefits that
affect all the dimensions of wellness and improve overall quality of
life.
Test your knowledge
 About how much blood does the heart pump each
minute during aerobic exercise?



5 quarts
10 quarts
20 quarts

20 QUARTS. During exercise, cardiac output increases to 20 or
more quarts per minute, compared to about 5 quarts per minute at
rest.
Test your knowledge
 During an effective 30 minute cardio respiratory
endurance workout, you should lose 1 – 2 pounds.
True or False?

FALSE. Any weight loss during an exercise session is due to fluid
loss that needs to be replaced to prevent dehydration and enhance
performance.
Basic physiology
 The Cardio – Respiratory System

Consists of:

Circulatory system
 Heart
 Blood vessels

Respiratory system
The heart
 Pulmonary
circulation


Right side
Pumps blood to
the lungs
 Systemic
circulation


Left side
Pumps blood to
the body
The heart beat
 Systole
 Heart’s contraction
 Blood flows out of the heart
 Diastole
 Hearts relaxation
 Blood flows into the heart
 Blood pressure
 Force exerted by blood on
the walls of the blood vessels
 Created by the pumping
action of the heart
 Heart beat:
 Nerve impulses
 Pacemaker – sinoatrial node
(SA)
Blood vessels
 Veins



Carry blood towards the heart
Thin walls
Valves
 Arteries


Carry blood away from the heart
Thick, elastic walls
 Capillaries


Smallest blood vessels
1 cell thick
Heart’s blood vessels
 The heart has its own
network of arteries,
veins and capillaries.
 Coronary arteries (2)
 Branch off the aorta
 Supply the heart muscle
with oxygenated blood
Respiratory system
FUNCTION
 Supplies oxygen to the body
 Carries off carbon dioxide
 Helps to regulate acid
produced during metabolism.
HOW IT WORKS
 Lungs expand and contract by
the contraction and relaxation
of the diaphragm and rib cage
 Alveoli are the site of gas
exchange.
The cardio-respiratory system at rest and during
exercise
At rest
During exercise
 Heart beats  50 – 90 per min.
 Heart beats  170 – 210 per min
 Breaths  12 – 20 per min.
 Breaths  40 – 60 per min.
 Blood pressure  120 systolic, 80
 Blood pressure  175 systolic, 65
diastolic (120/80)
 Blood flow  15 – 20% directed to
skeletal muscles.
 Cardiac output of 5 quarts per
minute.




diastolic (175/65)
Blood flow  85 – 90% directed to
skeletal muscles.
Cardiac output increases to 20 or
more quarts per minute.
Stroke volume increases
More blood per minute
Energy Production
Metabolic rate

Metabolism is the sum of all the chemical – physical changes
that take place within the body that enable it to grow and
function.

At rest  low

During movement  increases
800% during intense exercise
 Olympic caliber distance runners – 2000%

Energy Production
 Energy from food





Comes from carbohydrates, fats and protein
During digestion are broken down to glucose
Some glucose remains in blood as a quick source of fuel to
produce energy
The rest of it is converted to glycogen and stored in the liver,
muscles and kidneys.
The remaining glucose is converted to fat and stored in fatty
tissues.
Energy Production
 ATP  adenosine triphosphate
 Basic form of energy used by cells
 Released by a series of chemical reactions from stored fuels
(glucose, glycogen and fat)
Exercise and the three energy systems
 The immediate energy system
 The non-oxidative energy system
(anaerobic respiration)
 The oxidative energy system
(aerobic respiration)
Exercise and the three energy systems
 The immediate energy
system


Provides energy rapidly, only
in a short period of time (10
or less seconds)
Energy comes from existing
cellular ATP stores and
creatine phosphate (CP), a
chemical used to produce
more ATP.
Exercise and the three energy systems
 The non-oxidative energy system
(anaerobic respiration)




Used at the start of an exercise
For high intensity activities
Lasts from 10 seconds to 2 minutes
Creates ATP by breaking down glucose
and glycogen in the absence of Oxygen.
LIMITATIONS
 Its supply of glucose and glycogen are
limited
 Releases hydrogen ions that are thought
to interfere with metabolism and muscle
contraction causing fatigue.
 Also creates metabolic acids (lactic acid)
Exercise and the three energy systems
 The oxidative energy system (aerobic
respiration)






Used during any physical activity that lasts
longer than about 2 minutes
Requires O2 to generate ATP
It is not an immediate source of energy, but
lasts longer.
Takes place in the mitochondria
The body stores of fuel for this system are much
greater.
At high intensity exercise burns carbs, and at
low intensity exercise burns fats.
LIMITATIONS
 Glycogen depletion
 Supply of Oxygen (VO2max, Max. O2
consumption)
0 sec
4 sec
10 sec
1.5 min
3 min +
Strength – Power:
power lift, shot put, golf swing
Sustained Power:
sprints, fast breaks, football
Anaerobic Power – Endurance:
200-400 m dash, 100 m swim
Aerobic Power :
hiking, distance
running, swimming
Immediate/short-term
non-oxidative systems
Aerobic-oxidative
system
Energy systems in combination

Your body uses all three energy systems when you exercise
Think…
 What type of physical activities involve…
 The immediate energy system?




The non-oxidative energy system?




Weight lifting
Rising from a chair
Picking up a heavy package.
400 m run
Climbing stairs
Running behind a bus
The oxidative energy system?




Distance running
Swimming
Hiking
Standing in line
Benefits of cardio respiratory endurance
 Improved cardio respiratory functioning
 Maintains or increases the heart’s own blood and oxygen supply
 Increases heart muscle’s function.
 Strengthening hearts contractions
 Increases heart’s cavity size
 Increases blood volume
 Reduces blood pressure.
 Improved cellular metabolism
 Increases the number of capillaries in the muscles
 Trains muscles to work efficiently: get the most out of O2 and fuel.
 Increases the size and number of mitochondria in muscle cells
 Prevents glycogen depletion and increases the ability of muscles to use
lactic acid and fat as fuels.
 Protects cells from damage produced by free radicals.
Benefits of cardio respiratory endurance
 Reduced risk of chronic disease
 Cardiovascular diseases






Cancer


Exercise burns sugars and makes cells more sensitive to the hormone insulin
Osteoporosis


Studies show a relationship between increased physical
activity and a reduction in a person’s risk of cancer.
Type 2 diabetes


Healthy balance in blood levels of glucose and cholesterol
Reduces blood pressure
Betters the function of cells that line arteries
Reduces inflammation
Prevents obesity
Helps build bone and muscles
Death from all causes

Poor fitness is a good predictor of premature death.
Benefits of cardio respiratory endurance
 Better control of body fat

Regular exercise boosts your calorie expenditure (metabolism)
 Improved immune function



Moderate endurance exercise boosts your immune function
Overtraining depresses it.
Influences the levels of specialized cells and chemicals involved in
the immune response.
 Improved psychological and emotional well being




Improves your self image.
Opportunities to socialize
Lessens anxiety, depression, stress, anger and hostility
Improves sleep
Assessing Cardio respiratory Endurance
 Assessment tests

1-mile walk test


3-minute step test


Amount of time it takes you to complete 1 mile of brisk walking
and your heart rate at the end of your walk
Rate at which the pulse returns to normal after exercise
1.5 mile run-walk test

Indicates high maximal oxygen consumption (VO2max)
Assessing Cardio respiratory Endurance
 Monitoring your heart rate
sphygmomanometer
LAB 4.1.
 Use the 3-minute step test to assess your
level of cardio respiratory endurance

http://webmetronome.com/
Developing a Cardio respiratory Endurance Program
To develop a successful endurance program, you should…
 Set realistic goals
 Improve your maximal oxygen consumption (VO2max)
 Improve your resting heart rate.
 Become more energetic, sleep better, fit on clothes.
 Set your starting frequency, intensity and duration of
exercise at appropriate levels and choose suitable
activities (FITT)

Frequency: 3 – 5 days per week depending on the intensity of
the activity

Time: a total duration of 20 – 60 minutes is recommended on
a single session or multiple 10 min sessions.

Type of activity: consider your preferences, access to facilities,
equipment, time required for a proper workout

Intensity: intensely enough to stress your body
Target heart rate zone: rate at which you should exercise to
experience cardiorespiratory benefits (65% to 90% of your
maximum heart rate)
 Estimate your maximum heart rate by subtracting your age
from 220
 Multiply your MHR by 65% and 90%
 Heart rate reserve: difference between maximum heart rate and
resting heart rate
 The target heart rate is equal to resting heart rate plus between
50% and 85% of heart rate reserve


Intensity: intensely enough to stress your body
Monitor your heart rate
 Count your pulse while you’re still moving or immediately after
you stop
 Count beats for 10 seconds and multiply that number by 6
 METS: represent a measure of the metabolic cost of exercise
 One MET represents the body’s resting metabolic rate
 6-8 METs are moderate-intensity exercises
 More than 10 METs are vigorous exercise


Intensity: intensely enough to stress your body
Ratings of Perceived Exertion:
 Scale of ratings to monitor the intensity of your exercise session
without checking your pulse. (Fig 4.6)
 Talk Test
 Although your breathing rate will increase during exercise, you
should not work out so intensely that you cannot speak
comfortably.

LAB 4.2
 Developing an Exercise Program for Cardio-respiratory
Endurance.
Calculate your target heart rate
 Warming up and cooling down
 Warm up before every session
Enhances performance
 Decreases the chance of injury
 Gives the body time to redirect blood to active muscles
 The heart adapts to increased demands
 Helps to spread synovial fluid throughout the joints.


Cool down afterwards
Stretching is a good option
 Helps to maintain blood flow to the heart and brain
 Redirects blood from working areas of the body
 Helps to prevent a large drop in blood pressure

 Adjust your program as your fitness improves
Stage
Time Intensity
Initial
3-6
days
Exercise at the low
end of your target
heart rate zone
Improvement
stage
4–6
months
Slowly and gradually
increase the amount
of overload until you
reach your target level
of fitness.
3-4
Increments of 5 – 10 minutes
every 2 – 3 weeks
Continue to exercise
at the same intensity
Do cross training
3-5
20 – 60 min
Maintenance
stage
Frequency
Time
(days/week)
3
12-15 min – unfit
20 – 25 min – sedentary
30 – 40 min - experienced
Exercise Safety and Injury Prevention
 Hot weather and heat stress
 Dehydration


Heat cramps



Depletion of sodium and potassium from the muscles is
involved
Primary cause is muscular fatigue.
Heat Exhaustion


Increases body temperature and decreases sweat rate,
exercise capacity, muscular strength and many body
functions.
Produces a rapid weak pulse, low blood pressure, headache,
faintness, weakness, dizziness, profuse sweating, pale face,
psychological disorientation and slightly elevated body
temperature.
Heat stroke

Is a failure of the brain’s temperature regulatory center, the
body does not sweat enough, body temperature rises to
extremely dangerous levels.
Exercise Safety and Injury Prevention
 Cold weather
 Hypothermia
Depresses the central nervous system
 Sleepiness
 Lower metabolic rate
 Body temperature declines
 Coma, death.


Frostbite
Freezing of body tissues (earlobes, fingers, toes)
 Can cause permanent circulatory damage

Exercise Safety and Injury Prevention
 Poor air quality
 Air pollution can decrease exercise performance and negatively
affect health
 It could decrease lung function as much as smoking
 Symptoms include eye and through irritations, difficulty to
breath, headache and malaise.
Exercise Safety and Injury Prevention
 Exercise Injuries
 When to call a physician
Head and eye injuries
 Possible ligament injuries
 Broken bones
 Internal disorders: chest pain, fainting, elevated body
temperature, intolerance to hot weather.


Minor injuries: can be treated with the R.I.C.E. principle
Rest
 Ice
 Compression
 Elevation

Exercise Safety and Injury Prevention
 Exercise Injuries
 Preventing injuries











Train regularly and stay in condition
Gradually increase the intensity, duration or
frequency of your workout
Avoid high – impact activities
Get proper rest between exercise sessions
Drink plenty of fluids
Warm up and cool down
Maintain a good level of flexibility
Us proper body mechanisms for lifting objects or executing sports skills
Don’t exercise when you are ill or over trained
Use proper equipment
Don’t return to your normal exercise program until any athletic injuries have
been healed.
Download