Cardiorespiratory Fitness

Cardiorespiratory Fitness Assessment

• Purpose– Determine level of fitness & set goals– Develop safe & effective exercise

prescription– Document improvements–Motivation– Provide info concerning health status

Cardiorespiratory Fitness

• Health Related– Low levels• ↑d risk of premature death

– ↑s• reduction of death from all causes

– High levels• high levels of PA & better health

Cardiorespiratory Fitness

• Related to the ability to perform large muscle, dynamic, moderate-to-high intensity exercise for prolonged periods.

Performance depends on

Respiratory

Cardiovascular

Skeletal muscles

Measuring Cardiovascular Measuring Cardiovascular Endurance (Aerobic Capacity)Endurance (Aerobic Capacity)

•Best Measure?• VO2max

– O2 uptake – Pulmonary

– O2 transport – Cardiac

– O2 utilization - Muscular

Measuring Cardiovascular Endurance (Aerobic Capacity)

• VO2max

–Measure

–Estimate

–Laboratory Tests

–Field Tests

Measuring Aerobic CapacityMeasuring Aerobic Capacity

Laboratory MethodsMeasures of Maximal Exercise Capacity

• Maximal Oxygen Consumption

Submaximal estimations

• Astrand Rhyming Nomogram

• YMCA Cycle Protocol

Linear Relationships Among Linear Relationships Among VOVO22, HR & Workload, HR & Workload..

Measuring Aerobic CapacityMeasuring Aerobic Capacity

Field MethodsDistance runs

• 1 Mile Run

• 1.5 Mile Run

• 12 Minute Run

• 6 Minute Walk

• Rockport 1-Mile Walk Test

Measuring Aerobic CapacityMeasuring Aerobic Capacity

Field MethodsStep tests

• YMCA 3-Minute Step Test

Predicting VO2max w/o exercise

VO2max = 50.513 + 1.589 * self-reported physical activity – .0289 * age in yrs - .552 & %Fat + 5.836 * gender

(female = 0; male = 1)

Measuring Aerobic CapacityMeasuring Aerobic Capacity

Laboratory Tests

Vs.

Field Methods

Advantages/Disadvantages??

Cardiorespiratory Fitness

• Which test?– Time demands– Expense or costs– Personnel needed (i.e., qualifications)– Equipment & facilities needed– Physician supervision needed– Population tested (safety concerns)– Need for accuracy of data

Cardiorespiratory Fitness

• Field or Submaximal Tests advantages– Less expensive– Does not need same level of clinical supervision– Lower risk– Less sensitive & specific for disease detection– Less equipment– Generally shorter– In lab tests can assess a workload progression– Estimates of VO2

Cardiorespiratory Fitness

• Field or Submaximal Tests disadvantages

–Maximum measures estimated

– VO2max prediction error can be 10-20%

– Limited diagnostic capabilities– Limited for exercise prescription

Standard Procedures(must be followed)

• Standard testing protocol• Same modality & protocol – repeat testing• Constant pedal rate• Seat height• Time of day• Data collection standardized & consistent• Subjects free of infection – normal sinus rhythm• Pre test instructions• Room Temperature (64-68O) – air flow

Assumptions of Submax Tests

• Measurements made in steady state

• Linear relationship b/n HR & VO2

• HRmax similar at same age

• Mechanical efficiency same

Indications for Stopping an Exercise Test in Low-Risk Adults

• Angina-like symptoms• Drop (20 mmHg) in systolic BP or a failure

to rise • Excessive rise in BP– systolic pressure > 260 mmHg– diastolic pressure > 115 mmHg

• Signs of poor perfusion– light-headedness, confusion, ataxia, pallor,

cyanosis, nausea, or cold & clammy skin

Indications for Stopping an Exercise Test in Low-Risk Adults

• Failure of heart rate to ↑

• Noticeable Δ in heart rhythm

• Subject requests to stop

• Physical or verbal manifestations of severe fatigue

• Failure of the testing equipment

Measuring Aerobic CapacityMeasuring Aerobic Capacity

Criterion Based ReferenceMinimal levels of aerobic capacity associated with a reduced risk of disease & death

• Females = VO2max of 31.5 ml/kg/min

• Males = VO2max of 35.0 ml/kg/min

Norm Based Reference

Cardiorespiratory Fitness

• Field Tests– Complete a measured distance– Distance covered in a certain time

• Submaximal Tests– Step test– Single or multiple stage cycle test– HR measure

• Maximal Exertion– Graded or progressive exertion to volitional

fatigue (measure)

Pre-Test Considerations

1. Abstain from eating prior (>4 hrs)

2. Abstain from strenuous exercise (> 24 hrs)

3. Abstain form caffeine (>12-24 hrs)

4. Abstain from nicotine (> 3 hrs)

5. Abstain from alcohol (> 24 hrs)

6. Medications

Step TestsQueens College or McArdle Step Test

• Step: ht = 16.25 in for 3 min

• Men: 24 steps/min; – Women: 22 steps/min

• Radial pulse in 1st-5 sec, for 15 sec

• Men: VO2max = 111.33 – (0.42 * HR)

• Women: VO2max = 65.81 – (0.1847 * HR)

1.5 Mile Run• Record total time to complete 1.5 miles

• VO2max = 3.5 + 483/time

– Time in nearest hundredth of min

12 Min Walk/Run

• Cover maximum distance in 12 min

• VO2max = (3.126 * meters) - 11.3

Submaximal Cycle Ergometer Advantages

• Non-weight bearing

• Accurate workloads

• Easy to measure HR & BP

• Cost is lower than treadmill

• Requires smaller space

• No electricity needed

Submaximal Cycle Ergometer Disadvantages

• Non-familiar work mode

• Must maintain cadence

• Leg fatigue

Submaximal Prediction of CRF - Assumptions

• B/n HR of 110-150

• HRmax = 220-age

• Steady State

• Constant cadence

Submaximal Prediction of CRF – Sources of Error

• HRmax

• Efficiency

• Calibration

• Accurate measurement of HR

• HR at steady state

Cycle Ergometer Protocols (other)

Astrand-Rhyming Cycle Ergometer Test• Single Stage Test – 6 minutes• Males – unconditioned: 300 or 600 kgm/min (50 or

100 watts)• Males – conditioned: 600 or 900 kgm/min (100 or

150 watts)• Females – unconditioned: 300 or 450 kgm/min (50

or 75 watts)• Females – conditioned: 450 or 600 kgm/min (75 or

100 watts)

Cycle Ergometer Protocols (other)

Astrand-Rhyming Cycle Ergometer Test (cont)

• 50 rpm• Goal – HR b/n 125 to 170 – measured during 5th

& 6th minutes – average the 2 HRs for nomogram

• Nomogram – page 73 (Figure 4-1)• Age adjustment – page 72

Treadmill Testing

• Not usually used for submaximal testing

• Range of efficiencies is so high

• Would not recommend – but can be done

Step Tests• Astrand-Rhyming–Single step height – 33 cm for

women, 40 cm for men

–Rate = 22.5 steps/min for 6 minutes

• YMCA Protocol–12 in – 24 steps/min

–1 min - Recovery heart rate

Field Tests• Rockport 1-mile walk Test– HR at end

– VO2max (ml/kg/min) = 132.9 – 0.17 (body mass in kg) – 0.39 (age in yrs) + 6.3 (gender) - 3.26 (time in min) – 0.16 (HR)

• 1.5-mile run test– VO2max (ml/kg/min) = 3.5 + 483/(time in min)