CARIDIORESPIRATORY ENDURANCE

CHAPTER 4

CARIDIORESPIRATORY ENDURANCE

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

FUNCTION HOW IT WORKS

Supplies oxygen to the body

Carries off carbon dioxide Helps to regulate acid

produced during metabolism.

Lungs expand and contract by the contraction and relaxation of the diaphragm and rib cage

Alveoli are the site of gas exchange.

Respiratory system

At rest During exercise

Heart beats 50 – 90 per min.

Breaths 12 – 20 per min. Blood pressure 120 systolic,

80 diastolic (120/80) Blood flow 15 – 20%

directed to skeletal muscles. Cardiac output of 5 quarts per

minute.

Heart beats 170 – 210 per min

Breaths 40 – 60 per min. Blood pressure 175 systolic,

65 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

The cardio-respiratory system at rest and during exercise

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

Immediate/short-term Aerobic-oxidativenon-oxidative systems system

Aerobic Power : hiking, distance running, swimming

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?

Weight lifting Rising from a chair Picking up a heavy package.

The non-oxidative energy system? 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

Healthy balance in blood levels of glucose and cholesterol Reduces blood pressure Betters the function of cells that line arteries Reduces inflammation Prevents obesity

Cancer Studies show a relationship between increased physical activity and a reduction in a person’s risk of cancer.

Type 2 diabetes Exercise burns sugars and makes cells more sensitive to the hormone insulin

Osteoporosis 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 Amount of time it takes you to complete 1 mile of brisk

walking and your heart rate at the end of your walk 3-minute step test

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

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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 Frequency(days/week)

Time

Initial 3-6 days

Exercise at the low end of your target heart rate zone

3 12-15 min – unfit20 – 25 min – sedentary30 – 40 min - experienced

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

Maintenance stage

Continue to exercise at the same intensityDo cross training

3-5 20 – 60 min

Exercise Safety and Injury Prevention

Hot weather and heat stress Dehydration

Increases body temperature and decreases sweat rate, exercise capacity, muscular strength and many body functions.

Heat cramps Depletion of sodium and potassium from the muscles is

involved Primary cause is muscular fatigue.

Heat Exhaustion 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.