basic cardiorespiratory physiology benefits of aerobic training physical fitness assessment...

Basic Cardiorespiratory Physiology

Benefits of Aerobic Training

Physical Fitness Assessment

Cardiorespiratory Exercise Prescription

Adhering to a Lifetime Exercise Program

Chapter 6

Cardiorespiratory Endurance

CHAPTER

OUTLINE

Key TermsCardiorespiratory endurance: The ability of the lungs, heart, and blood vessels to deliver adequate amounts of oxygen to the cells to meet the demands of prolonged physical activity

Oxygen uptake (VO2): Amount of oxygen consumed by the bodyMaximal oxygen uptake (VO2max): Maximum amount of oxygen the body is able to use per minute of physical activity, expressed in l/min or ml/kg/min; the best indicator of cardio-respiratory or aerobic fitness






Key TermsAerobic Exercise: Exercise that requires oxygen to produce the necessary energy (ATP) to carry out the activity

Anaerobic Exercise: Exercise that does not require oxygen to produce the necessary energy (ATP) to carry out the activity






6.9Physical Activity Pyramid

Minimize inactivity

Strength and Flexibility: 2–3 days/week

Cardiorespiratory endurance: Exercise 20–60 minutes 3–5 days/week

Physical activity: Accumulate 60 minutes nearly every day


Higher maximal oxygen uptakeIncrease in the oxygen-carrying capacity of the bloodDecrease in resting heart rate and an increase in cardiac muscle strengthLower heart rate at given workloads






Increase in number and size of the mitochondria

Increase in the number of functional capillaries

Faster recovery time

Lower blood pressure and blood lipids

An increase in fat-burning enzymes

6.1Average Resting and Maximal Cardiac Output, Stroke Volume, and Heart Rate for Males

Critical ThinkingShould fitness testing be a part of your fitness program? Why or why not?

Are there benefits to pre-participation fitness testing, or should fitness testing be done at a later date?






Reasons to Assess Fitness

To educate participants regarding present fitness levels and compare them to health fitness and physical fitness standards

To motivate individuals to participate in exercise programs

To provide a starting point

To evaluate improvements achieved through exercise programs and make adjustments

To monitor changes in fitness throughout the years






“Exercise is the closest thing we’ll ever get to the miracle pill that everyone is seeking. It brings weight loss, appetite control, improved mood and self-esteem, an energy kick, and longer life by decreasing the risk of heart disease, diabetes, stroke, osteoporosis, and chronic disabilities.”[ H. Atkinson. Exercise for Longer Life: The Physicians Perspective. HealthNews 7, no. 3 (1997): 3]






Oxygen UptakeAbsolute: Expressed in liters per minute (l/min)

Used to determine energy (caloric) expenditure

Each liter of oxygen consumed by the body burns about 5 calories

Relative: Expressed in milliliters per kilogram of body weight per minute (ml/kg/min)

Used to determine cardiorespiratory endurance fitness categories






Components ofOxygen Uptake (VO2)

Heart rate (HR)

Stroke volume (SV)

Arteriovenous oxygen difference (a-vO2diff) -






Equation to Determine VO2

VO2 in l/min = (HR x SV x a-vO2 diff) ÷ 100,000






Resting Oxygen Uptake

Example

SV = 79 ml

HR = 76 bpm

a-vO2diff = 5 ml/100 cc

VO2 in l/min = (76 x 79 x 5) ÷ 100,000 =.3 l/min






Maximal Oxygen Uptake (VO2max)

Example

HR = 190 bpm

SV = 120 ml

a-vO2diff = 15 ml/100 cc

VO2max in l/min =(190 x 120 x 5) ÷ 100,000 = 3.42 l/min






VO2 Conversion:Absolute to Relative

l/min (absolute VO2) to ml/kg/min (relative VO2)

Multiply l/min by 1000 and divide by body weight in kg (1 kg = 2.2046 lbs)

Example:BW = 70 kg (154.3 lbs)

VO2max = 3.42 l/min

VO2max in ml/kg/min = 3.42 x 1000 ÷ 70 = 48.9 ml/kg/min






VO2 Conversion:Relative to Absolute

Can you convert VO2 from ml/kg/min to l/min?

VO2max = 54 ml/kg/min

BW = 60 kg

AnswerVO2max in l/min = 54 x 60 ÷ 1000 = 3.24 l/min






Critical ThinkingYour relative maximal oxygen uptake can be improved without engaging in an aerobic exercise program. How can you accomplish this?

Would you benefit from doing so?






VO2max Assessment

Direct gas analysis (oxygen consumption)

Indirect methods (to estimate VO2max)

1.5-mile run test

1.0-mile walk test

Step test

Astrand-Ryhming test

12-min swim test (estimates cardiorespiratory endurance fitness category)






1.5-Mile Run Test

Estimates VO2max based on how fast an individual is able to jog/run a 1.5-mile course

Test should be limited to individuals who have been cleared for exercise

Not recommended for unconditioned beginners or men over 45 and women over 55 without medical clearance






1.0-Mile Walk Test

Estimates VO2max based on a predicting equation that requires the time it takes to walk a 1.0-mile course, exercise heart rate, body weight, and gender






Step Test

Estimates VO2max based on a 3-minute step (16 1/4"-high) test and a 15-second heart rate taken between 5 and 20 seconds into recovery






Astrand-Ryhming Test

Estimates VO2max based on a 6-minute bicycle ergometer test according to gender, work load, exercise heart rate, age, and body weight






12-Minute Swim Test

Determines cardiorespiratory fitness category according to the distance swam in 12 minutes

Test should be limited to skilled/conditioned swimmers

Considered a maximal test, thus medical clearance is recommended






6.8Cardiorespiratory Fitness Categoryaccording to Maximal Oxygen Uptake

After obtaining your maximal oxygen uptake, you can determine your current level of cardiorespiratory fitness by consulting this table

“

Quote

No drug in current or prospective use holds as much promise for sustained health as a lifetime program of physical exercise.”[W.M. Bortz II. Disuse and Aging. Journal of the American Medical Association, 248 (1982): 1203-1208]






Predicting Caloric Expenditure from Oxygen Uptake

The human body burns about 5 calories for each liter of oxygen consumed

A person with a VO2max of 3.5 l/min exercising at 60% of maximum uses 2.1 (3.5 X .60) liters of oxygen per minute and burns 10.5 (2.1 X 5) calories per minute of physical activity

Using this principle, one can determine the total caloric expenditure of a given session of physical activity






Predicting Caloric Expenditure from Oxygen Uptake

One pound of fat represents 3,500 caloriesAt 10.5 calories per minute, a person needs to exercise for a total of 333 minutes (3,400/10.5) to burn the equivalent of one pound of fatLab 6B provides guidelines to determine the caloric expenditure of physical activity at any heart rate between 120 and 170 beats per minute






CardiorespiratoryExercise Prescription

Use FITT variablesFrequency (how often you exercise)

Intensity (how hard you exercise)

Type (mode of exercise)

Time (duration of exercise)






Responders vs. Nonresponders

A wide variation in physiological responses exists between individuals who follow similar training programs

Heredity plays a crucial role in how each person responds and improves following an exercise program







Principle of individuality: Studies have documented that some individuals readily experience improvements in fitness (responders), whereas others exhibit small or no improvements at all (nonresponders) following similar exercise training programs

As an average, VO2max increases between 15 and 20% following several months of aerobic trainingIndividual responses can range from 0 (in a few selected cases) to more than 50% improvement







Nonresponders constitute less than 5% of exercise participants

Lack of cardiorespiratory endurance improvements among nonresponders might be related to low levels of leg strength

A lower body strength-training program has been shown to help nonresponders improve VO2max through aerobic exercise






Responders vs. NonrespondersIf cardiorespiratory fitness doesn’t improve as expected, do not get discouraged: make it a priority to be physically active every dayBesides regular exercise, lifestyle behaviors like walking, taking stairs, cycling to work, parking farther from the office, household tasks, gardening, and yard work provide substantial benefitsMonitoring physical activity and exercise habits should be used in conjunction with fitness testing to evaluate compliance It is through increased daily physical activity that responders and nonresponders reap the health benefits that improve quality of life






Key Term

Intensity: How hard a person has to exercise to improve or maintain fitness






Training Intensity

Training Intensity (TI): 40 to 85% of heart rate reserve (HRR)

Low = 40 to 50%Moderate = 50 to 60%High = 60 to 85%

HRR = Maximal HR (MHR) – resting HR (RHR)Estimated MHR = 220 – ageIntensity = (HRR x TI) + RHR






Training Intensity

40% TI = (HRR x .40) + RHR

50% TI = (HRR x .50) + RHR

60% TI = (HRR x .60) + RHR

85% TI = (HRR x .85) + RHR






Exercise Intensity

ExampleAge = 20

RHR = 68

MHR: 220 – 20 = 200 bpmHRR= 200 – 68 = 132 beats

40% TI = (132 X .40) + 68 = 121 bpm50% TI = (132 X .50) + 68 = 134 bpm60% TI = (132 X .60) + 68 = 147 bpm85% TI = (132 X .85) + 68 = 180 bpm

Low-intensity training zone:121 to 134 bpm

Moderate-intensitytraining zone:134 to 147 bpm

High (optimal) training zone:147 to 180 bpm






To improve your cardiorespiratory fitness, maintain your heart rate between the 60 and 85% training intensities

6.6Cardiorespiratory Fitness Category According to Maximal Oxygen Uptake

Rate of perceived exertion (RPE): A perception scale to monitor or interpret the intensity of aerobic exercise

6.7Key Term

Key Term

Mode: Form or type of exercise






Exercise Prescription

Mode or type of exercise = Aerobic

Uses major muscles of the human body

Rhythmic and continuous in nature

Maintain heart rate in the proper training zone during exercise

Examples: walking, jogging, cross-country skiing, cycling, aerobics, swimming, water aerobics, stair climbing






Key TermsDuration: Time or length of each exercise session







Duration or time = 20 to 60 minutes per session

At about 85% of HRR = 20 to 30 minutes

At 50% HRR = 30 to 60 minutes

Accumulating 30 minutes of moderate-intensity physical activity also provides benefits; about 57% of those derived through a 30-minute continuous work out

For weight management, 60 minutes of physical activity on most days of the week are recommended






Key Term

Frequency: How many times per week a person engages in an exercise session







Frequency of exercise

For VO2max (and health) improvements, 3 to 5 days per week

VO2max improvements are minimal when training is conducted more than 5 days per week

For health benefits, accumulate 30 minutes of moderate-intensity physical activity on most days of the week

For weight management, accumulate 60 minutes of physical activity on most days of the week






Critical ThinkingKate started an exercise program last year as a means to lose weight and enhance body image. She now runs over 6 miles every day, works out regularly on stair climbers and elliptical machines, strength-trains daily, participates in step aerobics 3 times per week, and plays tennis or racquetball twice a week. Will you evaluate her program and make suggestions for improvements?



Physical Fitness

Assessment

Cardiorespiratory Exercise

Prescription

Adhering to a Lifetime Exercise

Program

Getting Started and Adhering to Lifetime Exercise

Set aside a regular time for exercise

Exercise early in the day

Select aerobic activities you enjoy

Combine different activities (cross-train)

Use proper clothing and equipment

Basic Cardiorespiratory

Physiology


Physical Fitness

Assessment


Prescription


Program


Find a friend or group of friends to exercise with

Set goals and share them with others

Purchase a pedometer (step counter) and attempt to accumulate 10,000 steps each day

Don’t become a chronic exerciser

Exercise in different places and facilities


Physiology


Physical Fitness

Assessment


Prescription


Program


Exercise to music

Keep a regular record of your activities

Conduct periodic assessments

Listen to your body

If a health problem arises, see a physician


Physiology


Physical Fitness

Assessment


Prescription


Program

Running the Extra Mile

End of Chapter

basic cardiorespiratory physiology benefits of aerobic training physical fitness assessment...

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