Assessing Cardiorespiratory Fitness Flashcards
Maximum Oxygen Uptake (VO2max)
Functional capacity of cardiorespiratory (CR) system (Capacity of heart, lungs, blood vessels to deliver O2); Criterion (gold standard) of cardiorespiratory fitness
The aerobic system is also responsible for assisting in…
Offloading of anaerobic byproducts
3 Energy Systems
ATP-Pc, Glycolytic, Aerobic
An increase in VO2 max causes and increase in…
Aerobic state (better aerobic conditioning)
VO2max
Plateau of VO2 (Trainable to some extent)
VO2peak
Highest rate of O2 consumption regardless of VO2 plateau (Specific to a type of modality)
Cardiorespiratory Fitness is related to the ability to perform
Large muscle, dynamic, moderate-to-high intensity exercise for prolonged periods
Cardiorespiratory Fitness Performance depends on
Respiratory, Cardiovascular, and Skeletal muscle Systems
(1) Cardiorespiratory Fitness is considered health-related fitness because: Low levels of CR fitness have been associated with a…
Markedly increased risk of premature death from all causes and specifically from CV disease
(2) Cardiorespiratory Fitness is considered health-related fitness because: Increases in CR fitness are associated with a…
Reduction in death from all causes
(3) Cardiorespiratory Fitness is considered health-related fitness because: High levels of CR fitness are associated with…
Higher levels of habitual physical activity (Which in turn are associated with many health benefits)
VO2max is accepted as the…
Criterion measure of CR fitness (Concept of Maximal O2 Uptake)
VO2max =
Q * a-vO2 difference (arterial -venous oxygen difference)
Significant variations in VO2max across populations and fitness levels result primarily from…
Differences in maximal Q in individuals w/out pulmonary disease
VO2max is closely related to the…
Functional capacity of the heart
Because of costs associated w/equipment, space, and personnel needed to carry out these tests…
Direct measurement of VO2max generally is reserved for Research or clinical settings
When direct measurement of VO2max is not feasible…
A variety of submaximal and maximal exercise tests can be used to estimate VO2max
It should be noted that there is the potential for what when using indirect measurement techniques?
A significant overestimation of directly measured VO2max by these types of indirect measurement techniques
Overestimation of VO2max is more likely to occur when:
1) Exercise protocol chosen is too aggressive for a given individual, (2) When treadmill testing is employed and the individual heavily relies on handrail support
Every effort to determine VO2max when choosing test protocol should therefore be taken to…
Choose the appropriate exercise protocol given an individual’s characteristics and minimize handrail use
Aerobic Power
Synonymous with Cardiovascular Endurance; Indicative of body’s ability to utilize oxygen for the performance of work
Maximal Oxygen Uptake (VO2max)
Most often used indicator of aerobic power; Maximal amount of oxygen your body can utilize when exercising; The greater the VO2max, the more aerobically fit
The pathway by which oxygen is transported from atmospheric air to the active muscles
CO2 enriched, O2 depleted blood returns to the heart > Oxygen-poor air to the lungs > Exhale CO2 > Inhales oxygen-rich air > Oxygen-rich blood from lungs to body > Exercising muscle uses oxygen (O2 in, CO2, ATP out)
What Determines VO2max
Combination of “Central” and “Peripheral” Factors
Central Factors to determine VO2max
Delivery of oxygen rich blood to the active musculature; Cardiovascular system (Cardiac Output (Q) = HR * SV); Cardiac Output; Muscle capillary density
Cardiac Output
- blood volume, 2. venous return, 3. resistance to blood flow
Peripheral Factors to determine VO2max
Extraction of oxygen by the muscle or body tissues from the delivered blood; Active muscle (arteriovenous oxygen difference): Amount of lean mass, #/size of mitochondria, #/activity of oxidative enzymes, Muscle fiber type
3 body systems involved in VO2max
Respiratory, Cardiovascular, Muscular
Respiratory System
Oxygenation of blood
Cardiovascular System
Delivery of blood to tissues
Skeletal Muscle System
Extraction and utilization of oxygen
Influences on VO2max
Largely genetically determined; Training can improve it up to 25%, depending on initial fitness level; Males score ~ 15–30% higher than females (Males have larger lung capacity and leaner tissue)
Direct (Direct Fick Method)
Catheterization of artery and vein to determine a- vO2 difference and Q (thermal dye)
Indirect (Indirect Calorimetry)
Laboratory test, Analysis of volume of air inspired and constant analysis of expired gas, Very accurate
Absolute (Units of VO2)
L/min or ml/min; Does not take size into account
Relative (Units of VO2)
mlkg -1min or ml*kgFFM -1 *min; Amount of oxygen your body uses per kilogram of bodyweight; Can compare value across genders and body mass/size
How to convert from Absolute to Relative VO2max
Multiply LO2/min by 1000 to get mLO2/min
Divide mLO2/min by bodyweight in kg; If absolute is in mLO2/min
Divide mLO2/min by body weight in kg
How to convert from Relative to Absolute VO2max
Multiply mLO2/kg/min by bodyweight in kg to get mLO2/min; If you want absolute as LO2/min: Divide mLO2/min value by 1000
Grace, who weighs 55 kg, has an absolute VO2max of 2.5 LO2/min. What is her relative VO2max?
2.5 LO2/min x 1000 = 2500 mLO2/min, 2500 mLO2/min / 55kg = 45.5 mLO2/kg/min
Lucy, who weighs 60 kg, has a relative VO2max of 47.0 mLO2/kg/min. What is her absolute VO2max in mLO2/min and LO2/min?
47.0 mLO2/kg/min x 60 kg = 2820 mLO2/min, 2820 mLO2/min / 1000 = 2.820 LO2/min
Cardiorespiratory Fitness Classifications of Women 20-29 VO2max
40-43
Cardiorespiratory Fitness Classifications of Men 20-29 VO2max
46-49
Most accurate estimate of VO2max Is achieved from the HR response to submax exercise test if all of the following assumptions are achieved:
A steady state HR is obtained for each work rate, A linear relationship exists b/t HR and work rate, Difference b/t actual and predicted max HR is minimal, Mechanical efficiency is the same for everyone, Subject is not on medications, using caffeine, under large amounts of stress, ill, or in a high temperature environment, all of which HR
Gillesh Method for determining VO2max
207-0.7(AGE)
Modes of Testing VO2max
Non-exercise Test VO2max Prediction Equations, Field Tests for CR Fitness, Motor-Driven Treadmills, Mechanically Braked Cycle Ergometers, Step Testing
HRmax Prediction
Considerable variability (±11 bpm), Numerous prediction equations exist (Most common: 220 − age), Measure HRmax whenever possible
Non-Exercise test VO2max prediction equations
Not nearly as accurate as Laboratory measurements; Can be used to broadly classify people into categories such as “poor, average, good cardiorespiratory fitness”; % Fat Model, BMI Model
Types of Non-Exercise Test VO2max Prediction Equations
%Fat Model or BMI Model (Increase BMI = Decreased VO2max)
PA-R score is a self-reported physical activity on a…
0-7 scale; Gender: 0 for females; 1 for males
Graded Exercise Test (GXT)
Done to evaluate VO2max; Gradually increase submaximal workloads; Maximal versus submaximal test; Things to consider: Client’s age and risk classification, Reason for test, Availability of equipment and qualified staff
General GXT Testing Guidelines: Continuous Protocol
8-12 min duration [ACSM], 2-3 min stages, 2-3 MET increases
General GXT Testing Guidelines: Ramp Protocol
~10 min duration, Small and frequent (10-20 s) increases, Electromagnetically braked cycle ergometer or programmable treadmill
Submaximal Cycling Tests (Types of Mechanically Braked Cycle Ergometer Tests)
Astrand-Ryhming Cycling Test, YMCA Bike Test; Based on HR response (Accurate measurement of HR is critical)
Submaximal Walking/ Running/ Stepping Tests
Treadmill Submaximal Tests, Astrand-Ryhming Step Test, YMCA 3-minute Step Test (CR fitness based on recovery HR)
Mechanically Braked Cycle Ergometers Benefits
Excellent for submaximal and maximal testing, Relatively inexpensive, Easily transportable, Allow BP and ECG (HR) to be measured
Mechanically Braked Cycle Ergometers Negatives
Less familiar mode of exercise to most Americans, Localized muscle fatigue, Underestimates VO2, Cycle ergometer must be calibrated, Subject must maintain proper pedal rate
Calculating Workload on Mechanically Braked Cycle Ergometer
Workload (kgm/min)= Resistance x RPM x 6; Workload (watts)= kgm/min../6
Example: Bob is cycling against a resistance of 1.5 kg and an RPM of 50. What is his workload in kg·m·min-1 and Watts
kgmmin-1 = 1.5 x (50 x 6) = 450 kgmmin-1; 450 kgmmin-1 / 6 = 75 Watts
Astrand-Ryhming Cycle Ergometer Test
Single-stage test lasting 6 min; Pedal rate is set at 50 rpm; Suggested work rate is based on: Gender/Individual’s fitness status; Use nomogram to find VO2max (draw a line from workload to avg HR); Mist convert to relative VO2max (x 1000, divide by body mass)
YMCA Cycle Test
Multistage Test; Initial workload set at 150 kg*m/min
Step Tests Benefits
Inexpensive, Requires little or no equipment, Steps are easily transportable, Stepping skill requires little practice, Test is of short duration, Great for mass testing
Step Tests Negatives
Special precautions may be needed for those who have balance problems or are extremely deconditioned, Most tests do not monitor HR and BP b/c of the difficulty of measuring HR and BP, Inadequate compliance to step cadence and excessive fatigue in the lead limb may diminish value of a step test
Step Tests Types Formula
Work = force x distance; (Force = body weight; Distance = bench height x steps/min)
Types of Step Tests
Astrand Rhyming and YMCA
Field Tests Benefits
Relatively cheap and little equipment is needed, Easy to administer to large groups, Can classify CR fitness level
Field Tests Negatives
Some tests can be maximal, Not as accurate as laboratory tests, Individual’s motivation and pacing ability, May be inappropriate for Sedentary individuals and Individuals at increased risk for CVD
Types Field Tests
1.5 Mile runs, Cooper 12 min run test, Rockport 1-mile fitness walking
Field Tests for Cardiorespiratory Endurance
1-Mile Run Time Test, 1.5 Mile Run Time Test
Measuring Pulse
Use index and middle fingers; Use radial pulse or light pressure on carotid, Use 6 -15 second count post exercise; Start stopwatch on 1st pulse, 1st beat is 0
Assessing CR Fitness of Children Lab Tests
Modified treadmill and cycle ergometer protocols
Assessing CR Fitness of Children Field Tests
1 mile run/walk, Multistage 20 m shuttle run, Andersen test
Assessing CR Fitness of Older Adults
Modified lab tests, Field tests (6 min walk test, 2 min step test)
Multistage Fitness Test
AKA the beep test, Variations: Yo Yo Intermittent Test and Yo Yo Recovery Test
Multistage Fitness Test Protocol
Two cones or field markers set 20 meters (21 yards, 32 inches) apart, Beep Test app or MP3 recording, Continue professing until Failure
Circuit Training does not have an effect on…
Aerobic System (Not large muscle, Isolated, Not capable of being performed for a long time)
Q (Cardiac Output)=
HR - SU ( HR bpm - Amount of blood injected form left ventricle)
Cardiac Output Increases when… (Ways to improve offloading oxygen)
Increases in Capillary density, Mitochondrial density, Oxidative Enzymes, and Type II > I muscle fibers occur
Increase in capillary density (Ways to improve offloading oxygen)
Gets oxygen to tissues that need it more efficiently
Increase in Mitochondrial Density (Ways to improve offloading oxygen)
Chronic aerobic activity causes mitochondria around muscle fibers
Increase Oxidative Enzymes (Ways to improve offloading oxygen)
ATPase, ability to break down components and utilize them for ATP production
Increase Type II to act like Type I fibers (Ways to improve offloading oxygen)
Type I are really good at utilizing oxygen for fuel; Away from anaerobic enzymes and become better
Increase in Stroke volume occurs as a result of…
Adaptation to physical activity; Increases because you can pool more blood in the ventricle) Frank Sterling Mechanism
Hypertrophy of Heart
When used more it becomes more efficient; Left Ventricle becomes stronger and ejects more blood with each beat
Resting Heart Rate (RHR) decreases when…
Exercise at same intensity and adapt (Stoke Volume goes up as a result)
VO2max decreases as we…
AGE; Steady until 30-40; Depending on PA decreases at late 30’s-early 40’s then rapidly in late 50’s
The biggest driver in decrease in VO2max as we age…
Loss of lean tissue
Types of Motor-Driven Treadmill Tests
Bruce/Modified Bruce, Blake and Ware, Naughton
Bruce/Modified Bruce (Motor-Driven Treadmill Tests)
Multistage, Accommodating Resistance, Initial Point is 1.7mph at 10% grade
Naughton
For CVD or increase risk of CVD
Motor-Driven Treadmill Test Benefits
Used for a wide range of fitness levels
Motor-Driven Treadmill Test Negatives
Make taking physiological measurements hard, Overestimation of VO2max
