1. 4 Assessing Cardiorespiratory Fitness chapter 4 chapter
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2. Cardiorespiratory Endurance
Ability to perform dynamic exercise involving large muscle groups at moderate-to-high intensity for prolonged periods (ACSM 2000)
Criterion measure is VO2max
VO2max is the most valid measure of the cardiorespiratory system’s functional capacity.
VO2max reflects
maximal ability of cardiorespiratory system to deliver O2 and nutrients to muscles and
ability of muscles to use them. .
(continued)

3. .
Absolute VO2
A discrete volume of O2 consumption in reference to time
Expressed in L/min or ml/min
Used for nonweight-bearing modalities
Directly related to body weight

4. Synonyms of Cardiorespiratory Fitness
Maximal Aerobic Capacity
Functional Capacity
Physical Work Capacity
Maximal Oxygen Uptake or Consumption
VO2max or VO2peak
Cardiovascular, Cardiorespiratory, or Cardiopulmonary
Endurance, Fitness or Capacity

5. .
Relative VO2
A volume of O2 consumption relative to unit of body mass and time
Expressed as ml/kg/min
Used for weight-bearing modalities
Best for comparing people of different body size
Can express as ml/kgFFM/min to look at O2 consumption of muscle mass

6. . Gross Versus Net VO2 . . Not synonymous terms
Gross VO2 = caloric cost of exercise and rest (Gross = exercise + rest)
Net VO2 = caloric cost of exercise only (Net = Gross – rest)
Express in either absolute or relative terms
Rest is 3.5 ml/kg/min or 1 MET . .

7. Cardiorespiratory fitness is considered health-related because:
Low levels of CRF have been associated with markedly increased risk of premature death from all causes, specifically CVD
Increases in CRF are associated with a reduction in death of all causes
High levels of CRF are associated with higher levels of habitual physical activity, which in turn are associated with many health benefits

8. Factors to decide which CRF test:
Time demands
Expense or cost
Personnel needed (i.e. qualifications)
Equipment and facilities needed
Physician supervision needed
Population tested (i.e. safety concerns)
Need for accuracy of data

9. CRF Pre-Test Considerations:
Abstain from eating (> 4 hours)
Abstain from strenuous exercise (24 hours)
Abstain from caffeine (12-24 hours)
Abstain from nicotine (> 3 hours)
Abstain from alcohol (>24 hours)
Medication considerations (if client’s meds affect resting or exercise HR, it will invalidate the test.

10. Graded Exercise Testing
Objective assessment of functional capacity
Can use maximal or submaximal tests
Can observe and compare numerous variables from baseline testing to follow-up testing
Instrumental for exercise programming and goal setting
(continued)

11. Graded Exercise Testing (continued)
ACSM recommends maximal exercise testing prior to start of vigorous exercise program for older, moderate-risk, or high-risk individuals.
Vigorous is >60% VO2max, or >6 METs. .
(continued)

12. Graded Exercise Testing (continued)
ACSM recommends submaximal testing for low- or moderate-risk individuals prior to starting a moderate-intensity exercise program
Moderate intensity is 40% to 60% VO2max, or 3 to 6 METs. .

13. GXT Guidelines Review contraindications to exercise testing.
Use maximal or submaximal GXT as appropriate.
If goal is diagnosing CAD, use max GXT.
Little difference exists in danger levels (max v. submax).
Use multiple stages (hence “graded”).
For non-ramp protocols, stages usually last 2 to 3 minutes each.
Know GXT termination criteria.

14. . .
VO2 peak Versus VO2 max .
Peak criteria are similar to criteria for VO2 max except RER is <1.15 and no plateau is attained.
Children, older adults, sedentary people, and those with known disease are likely to attain VO2 peak, but not max. .

15. Procedures for Conducting GXTs
Pretest instructions
Paperwork
Resting baseline data (HR, BP, EKG)
Instructions and warm-up stage
Periodic (and continual) monitoring
Stage changes (depend on protocol)
Termination (criteria depend on protocol, client, S/S)
Cool-down (recovery)

16. Rating of Perceived Exertion (RPE)
Original 6 to 20 scale was revised to 0 to 10 scale.
Both highly related to HR and VO2
Subjective scales of overall exertion
Moderate intensity is 12 to 14 on original scale and 6 on revised scale.
OMNI pictorial scales may also be used for children through adult age groups. .

17. Maximal Exertion Protocols
Choose protocol and modality wisely!
Individualized protocol is best
Highest VO2 is with uphill running; lowest is with arm ergometry
Usually lasts 8 to 12 minutes long
Can be a continuous or discontinuous protocol
Discontinuous protocols take longer .

18. Submaximal Exertion Protocols
Choose protocol and modality wisely!
Similar to maximal exertion GXTs
May or may not involve stage change(s)
Monitor constantly for S/S and proper hemodynamic response
Generally terminated based on predetermined criteria (e.g.,: 85% age-predicted maximal HR)
Results can be used to estimate exercise tolerance

19. Treadmill Protocols Manipulate workload via speed (mph) and grade (%).
ACSM’s TM walking and running equations estimate metabolic cost of exercise (energy expenditure).
Assume steady state stages (overestimates if not)
Cannot account for anaerobic component
Walking equation better if walking with incline
Use running equation for speeds >5mph or slow jog (3mph)
(continued)

20. Treadmill Protocols (continued)
Many treadmill protocols exist.
Choose best one for your client.
Many have their own equation to calculate VO2.
Some use nomograms. .

21. . Calculating VO2 . . . . . . 70 kg woman walks at 3.5 mph at no grade
VO2 = Horizontal + Vertical + Rest
VO2 = (speed x 0.1) ml/kg/min
VO2 = [(3.5mph x 26.8m/mi) x 0.1]
VO2 = (93.8 m/min x 0.1) ml/kg/min
VO2 = ml/kg/min
VO2 = ml/kg/min . . . . . .

22. What’s the Energy Cost? . 70 kg woman walks at 3.5 mph at no grade
VO2 = ml/kg/min
Kcal/min = .
12.88 ml
kg*min
70 kg
0.005 kcal
1 ml
= kcal/min
How long must she walk to expend 560 kcal?
4.508 kcal
1 min =
560 kcal
X min
560
4.508 =
124 min

23. Second Stage of Bruce Protocol
90 kg man walks at 3.4 mph at 14% grade
VO2 = Horizontal + Vertical + Rest
VO2 = (speed x 0.1) + (speed x grade x 1.8) + 3.5
VO2 = [(3.4mph x 26.8m/mi) x 0.1]
+ (speed x grade x 1.8) + 3.5
VO2 = (91.12 m/min x 0.1) + (91.12 x .14 x 1.8) + 3.5
VO2 = ml/kg/min
VO2 = ml/kg/min . . . . . .

24. Individualized Protocol
60 kg man running at 7 mph at 14% grade
VO2 = Horizontal + Vertical + Rest
VO2 = (speed x 0.2) + (speed x grade x 0.9) + 3.5
VO2 = [(7mph x 26.8m/mi) x 0.2] + (speed x grade
x 0.9) + 3.5
VO2 = ( m/min x 0.2) + (187.6 x .14 x 0.9) + 3.5
VO2 = ml/kg/min
VO2 = ml/kg/min . . . . . .

25. Another Individualized Protocol
60 kg woman jogging at 3.2 mph at 2% grade
VO2 = Horizontal + Vertical + Rest
VO2 = (speed x 0.2) + (speed x grade x 0.9) + 3.5
VO2 = [(3.2mph x 26.8m/mi) x 0.2] + (speed x grade
x 0.9) + 3.5
VO2 = (85.76 m/min x 0.2) + (85.76 x .02 x 0.9) + 3.5
VO2 = ml/kg/min
VO2 = ml/kg/min . . . . . .

26. What’s the Energy Expenditure?
60 kg woman walks at 3.2 mph at 2% grade
VO2 = ml/kg/min
Kcal/min = .
60 kg
22.19 ml
kg*min-1
0.005 kcal
1 ml
= 6.66 kcal/min
How long must she walk to expend 560 kcal?
6.66 kcal
1 min =
560 kcal
x min
560
6.66 =
84 min

27. Cycle Ergometer Protocols
Manipulate workload through cadence (rpm) and resistance (kp, W).
ACSM leg ergometry equations estimate metabolic cost of exercise (energy expenditure).
Power = force x distance/time
Power expressed as kpm/min or W.
Distance is 6 m for Monark and Bodyguard ergometers.
(continued)

28. Cycle Ergometer Protocols (continued)
Electrically braked ergometers allow variable cadences for any workload.
Mechanically braked ergometers require close monitoring of cadence.
Cadence based on client fitness level and cycling experience.
60 rpm produces highest VO2 max compared to other specific cadences. .

29. What’s the Energy Expenditure?
80 kg man cycling at 100 W
VO2 = Resistance pedaling + Unloaded pedaling + Rest
VO2 = [(100W / 80kg)x 10.8] + 3.5
+ 3.5 ml/kg/min
VO2 = (1.25 x 10.8)
VO2 = (13.5) ml/kg/min
VO2 = ml/kg/min
VO2 = 20.5 ml/kg/min . . . . . .
(continued)

30. What’s the Energy Expenditure? (continued)
60 kg woman cycling at 2 kp with cadence of 60 rpm
VO2 = Resistance pedaling + Unloaded pedaling
+ Rest
Power output = 2kp/min * 6m/rev * 60 rpm
= 720 kpm/min
VO2 = [((720/6) / 60kg)] x 10.8] ml/kg/min
VO2 = [((120/60) x 10.8)]
VO2 = (21.6) ml/kg/min
VO2 = ml/kg/min
VO2 = 28.6 ml/kg/min . . . . . .

31. Tips for Using Ergometer Protocols
For GXTs, confirm steady state HR attained prior to stage change.
If half of terminal stage is not completed, use resistance and cadence (power output) from prior stage for VO2 calculations. .

32. Other Testing Protocols.
Step tests: Several exist; require use of metronome; VO2 calculations are based on step height and cadence.
Recumbent stepper: Alternative for testing those with neuromuscular conditions affecting gait, coordination, and balance.
Stair stepper: Good for aerobic step practitioners.
Rowing ergometer: One exists for noncompetitive or unskilled rowers.

33. Submaximal Protocols
Not direct assessments of cardiorespiratory capacity
May be more practical than maximal exertion protocols
Can be performed on many modalities
Can involve multiple stages or just one
Can determine VO2 via calculations or nomograms
Rely on underlying assumptions .

34. Submaximal Assumptions
Steady-state HR is achieved and is consistent for work rate.
Relationship between HR and VO2 is linear for HRs between 110 and 150 bpm.
Mechanical efficiency is the same for all tested.
HRmax is similar for all of same age. .

35. Field Tests Practical Inexpensive Expedient Easy to administer
Good for assessing numerous people simultaneously
Suitable for a variety of settings
Generally based on postexertion HR measures
Least desirable manner of assessing cardiorespiratory fitness
Not for diagnosing CHD

36. Testing Children Treadmills are a better modality than cycles.
ACSM recommends modified Balke or modified Bruce protocols with 2-minute stages.
Field tests may be used.

37. Testing Older Adults
Use an extended warm-up at a low exertion starting stage.
Be ready to adjust treadmill speed for client safety.
May need to adjust grade and not speed.
Target a total test time of 8 to 12 minutes.
Extend stage duration to allow steady-state HR achievement.
Cycle ergometry may be preferable for client safety and comfort.
Field tests are also a possibility.