1. Cardiorespiratory Fitness (Assessment)

2. Purpose of Evaluation
to assess current fitness levels relative to age and sex
aid in development of an exercise program
identify areas of health/injury risk and possible referral to the appropriate health professional
to establish goals and provide motivation
to evaluate progress

3. Pretest and Safety Procedures
we have already discussed screening in this area (HR, BP, observation)
note the very cautious stance in the USA (everyone over 45 should have physician supervised graded exercise test)
written emergency procedures
written consent
ACSM also state that anyone over 35 with one or more major risk factor should get the physician supervised test.
PAR-Q much more relaxed, even up to age 69.

4. Cardiovascular responses to Acute exercise
Cardiac output - rises with work rate
Rest 5 L/min; Max 20 L/min
Heart rate increases linearly with work rate and O2 consumption (fig Neiman)
Max HR = Age (one standard deviation is +/- 12bpm)
Stroke volume rises with exercise to maximum at ~50% of aerobic capacity
Rest ml; exercise ml
Blood Pressure - Systolic increases linearly with intensity (max mmHg) - Diastolic may increase slightly (+ 10 mmHg) or not change
A-VO2 difference - Rest 5 ml/dl; Max 15 ml/dl
Blood flow to working muscle increases with exercise

5. Oxygen Consumption
Maximal oxygen consumption is most widely recognized measure of cardiopulmonary fitness
VO2 Max - highest rate of O2 use that can be achieved at maximal exertion
VO2 = HR X SV + (A-V O2)
Table 15.2 ACSM
Direct measurement of maximal oxygen uptake is the most accurate - Douglas Bag
Can also be estimated from peak work rate
Treadmill speed and grade, cycle work rate

6. O2 consumption Sub max estimates
sub-maximal tests have three assumptions
Linear relationship between HR, O2 uptake and workload
That the max HR at a given age is uniform
That the mechanical efficiency (O2 uptake at a given workload) is the same for everyone
Not entirely accurate - can result in 10-15% error in estimating VO2 max
Tend to overestimate in highly trained, underestimate in untrained
220- age ± 15 bts/min (I have always thought ± 10 for one standard deviation)
maximal heart rate stays the same each day for each individual (not true ± 15 bts/min)
graph of oxygen uptake versus heart rate is linear
mechanical efficiencies are similar
Also note that daily variations will affect even a VO2 max test.

7. Sub-maximal Tests
We have done (or will do) the following sub-max tests
YMCA sub-maximal bicycle test
Sub-maximal step test (mCAFT)
Rockport Fitness Walking Test
Cooper test
1.5 mile test
Caution client to stop if feeling dizzy, nauseous, very short of breath…

8. Metabolic Equivalent (MET)
Absolute resting O2 consumption
250 ml / min divided by body weight
An MET is the average amount of oxygen consumed while at rest. It is used a lot in ACSM exercise prescription guidelines.
MET = 3.5 ml / kg min
Capacity to increase work rate above rest is indicated by number of METs in max test
Sedentary can increase to 10, an athlete up to 23 MET

9. Cardiorespiratory Capacities
METs* VO2max
Athlete
Physically Active
Sedentary
Cardiac Patient
- Class II
- Class III
- Class IV <3 <11

10. Stress Tests Bruce protocol is a maximal stress test
Used as a diagnostic test for coronary heart disease and estimating VO2 max
must be cautious as Coronary Heart Disease is the #1 killer in Canada
if client has positive PAR-Q or is over 45 in the states
ECG (electrocardiograph) is used as 30% with confirmed CAD have normal resting ECG
but 80% of these abnormalities will show during exercise

11. Why Use Stress Tests?
To establish, from ECG, a diagnosis of heart disease and to screen for "silent" coronary disease in seemingly healthy individuals.
To reproduce and assess exercise-related chest symptoms.
To screen candidates for preventive and cardiac rehabilitative exercise programs.
To detect abnormal blood pressure response
To define functional aerobic capacity and evaluate its degree of deviation from normal standards.

12. Exercise-Induced Indicators of CHD
Angina Pectoris present 30% of time.
Electrocardiographic Disorders
S-T segment depression
Cardiac Rhythm Abnormalities
premature ventricular contractions
ventricular fibrillation
Other Indices of CHD
blood pressure (hypertensive and hypotensive)
heart rate (tachycardia or bradycardia)

13. Blood Pressure Response
normal for systolic to rise to mmHg
normal for diastolic to increase by 10 mmHg (can actually drop or stay the same)
systolic should not exceed 260 mmHg
diastolic increase >20 mmHg = hypertensive
exertional hypotensive response
failure of Systolic pressure to rise by at least mmHg, Or SBP drops (20 mmHg)
Correlated with myocardial ischemia, left ventricular dysfunction and risk of cardiac events
Hypotensive response may reflect diminished cardiac reserve

14. Heart Rate Response
average resting HR bpm but males usually 7-8 beats/min lower than females
tachycardia early in exercise is indicator of potential problems
bradycardia during exercise could be sinus node malfunction or other heart disease problems - or extreme fitness
Remember max HR declines with age

15. Rate Pressure Product RPP = SBP x HR
Commonly used estimate of myocardial workload and resulting oxygen consumption.
RPP = SBP x HR
Where: RPP = rate pressure product
SBP = systolic blood pressure
HR = heart rate
expect RPP to rise to > 25,000
- age, clinical status, and medications(b blockers) can influence results
This index of relative cardiac work is highly related to directly measured myocardial oxygen consumption and coronary blood flow in healthy subjects over a wide range of exercise intensities

16. Guidelines for Stopping a Stress Test
Repeated presence of premature ventricular contractions (PCVs).
Progressive angina pain regardless of the presence or absence of ECG abnormalities consistent with angina.
An extremely rapid increase in heart rate may reflect a severely compromised cardiovascular response.
Subject requests to stop

17. Guidelines for Stopping a Stress Test
Electrocardiographic changes that include the presence of
S-T segment depression of 2 mm or more,
AV block -
Failure of heart rate or blood pressure to increase with progressive exercise
or a progressive drop in systolic blood pressure (20mmHg) with increasing work load.

18. Guidelines for Stopping a Stress Test
An increase in diastolic pressure of 20 mm Hg or more, a rise above 115 mm Hg.
Rise in systolic pressure > 260 mmHg
Headache, blurred vision, pale, clammy skin, or extreme fatigue.
Marked dyspnea (breathlessness) or cyanosis.
Dizziness or near fainting, light-headedness or confusion
Nausea
Failure of equipment

19. Interpretation of Bruce
Prediction equations for VO2 max available based on activity and health status and gender (see lab book)
Outcomes
True positive - correctly predicts problem
False Negative - results are normal - patient has disease
True Negative - results normal - no disease
False Positive - abnormal test - no disease
With any positive results secondary tests are performed to confirm diagnosis

20. CPAFLA - mCAFT mCAFT- modified Canadian Aerobic Fitness Test
Ability and efficiency of lungs, heart, bloodstream, and exercising muscles in getting oxygen to the muscles and putting it to work.
Benefits of larger aerobic capacity
daily activities
reserve for recreation and emergencies
decline 10 % per decade after age 20
regular vigorous activity to deter this decline

21. mCAFT Structure Step for 3 min intervals Take HR at end of each stage
predetermined height and frequency (work rate)
Note - final stages use one large step up from back of steps
Men stages 7 and 8, women stage 8
Take HR at end of each stage
assess if client will continue based on ceiling HR (fig 7-10)
utilize heart rate monitor, or radial pulse
Take BP and HR after recovery
to determine if client is back to resting levels before release
Cuff can be attached before trial, or quickly after

22. Before Starting mCAFT Ensure Par-Q and consent completed
Determine starting stage Fig’s 7-8,9
have clients practice (p. 7-26)
note ceiling HR for that client (fig 7-10)
Upon completion client walks around for 2 minutes
Sit down and get recovery BP and HR (set times listed in CPAFLA)

23. Modified CAFT (mCAFT) to be continued? The CAFT was too
sub-max for many
people.

24. mCAFT
Aerobic Fitness Score = 10 X [17.2 +( 1.29 X O2 cost) - (0.09 X wt (kg)) - (0.18 X age (yrs))]
O2 cost is determined using Fig 7-11
The final heart rate is not considered, only the stage attained in assessing benefit zone
Heart rate can be used to determine improvement upon reappraisal if client does not move zones
Determine health benefit zone using fig 7-12