Cardiorespiratory Fitness Assessment Cardiorespiratory Fitness 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 Measuring Cardiovascular Endurance (Aerobic Capacity) • Best Measure? • VO2max – O2 uptake – Pulmonary – O2 transport – Cardiac – O2 utilization - Muscular • Purpose – Determine level of fitness & set goals – Develop safe & effective exercise prescription – Document improvements – Motivation – Provide info concerning health status 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 Endurance (Aerobic Capacity) • VO2max –Measure –Estimate –Laboratory Tests –Field Tests 1 Measuring Aerobic Capacity Laboratory Methods Measures of Maximal Exercise Capacity • Maximal Oxygen Consumption Submaximal estimations • Astrand Rhyming Nomogram • YMCA Cycle Protocol Linear Relationships Among VO2, HR. & Workload Measuring Aerobic Capacity Field Methods Distance runs • 1 Mile Run • 1.5 Mile Run • 12 Minute Run • 6 Minute Walk • Rockport 1-Mile Walk Test Measuring Aerobic Capacity Field Methods Step tests • YMCA 3-Minute Step Test Measuring Aerobic Capacity Laboratory Tests Vs. Field Methods Predicting VO2max w/o exercise VO2max = 50.513 + 1.589 * self-reported physical activity – .0289 * age in yrs - .552 & %Fat + 5.836 * gender Advantages/Disadvantages?? (female = 0; male = 1) 2 Cardiorespiratory Fitness 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 • Field or Submaximal Tests advantages – – – – – – – – Standard Procedures (must be followed) Cardiorespiratory Fitness • Field or Submaximal Tests disadvantages – Maximum measures estimated – VO2max prediction error can be 10-20% – Limited diagnostic capabilities – Limited for exercise prescription Assumptions of Submax Tests • • • • Measurements made in steady state Linear relationship b/n HR & VO2 HRmax similar at same age Mechanical efficiency same 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 • • • • • • • • • 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 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 3 Indications for Stopping an Exercise Test in Low-Risk Adults Measuring Aerobic Capacity Criterion Based Reference Failure of heart rate to ↑ Noticeable ∆ in heart rhythm Subject requests to stop Physical or verbal manifestations of severe fatigue • Failure of the testing equipment • • • • Minimal 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 Pre-Test Considerations 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 1. 2. 3. 4. 5. 6. Abstain from eating prior (>4 hrs) Abstain from strenuous exercise (> 24 hrs) Abstain form caffeine (>12-24 hrs) Abstain from nicotine (> 3 hrs) Abstain from alcohol (> 24 hrs) Medications • Maximal Exertion – Graded or progressive exertion to volitional fatigue (measure) Step Tests Queens College or McArdle Step Test • Step: ht = 16.25 in for 3 min • Men: 24 steps/min; – • • • 1.5 Mile Run • • Record total time to complete 1.5 miles VO2max = 3.5 + 483/time – Time in nearest hundredth of 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) 4 12 Min Walk/Run • • Cover maximum distance in 12 min VO2max = (3.126 * meters) - 11.3 Submaximal Cycle Ergometer Advantages • • • • • • Submaximal Cycle Ergometer Disadvantages • • • • • • • • Non-weight bearing Accurate workloads Easy to measure HR & BP Cost is lower than treadmill Requires smaller space No electricity needed Submaximal Prediction of CRF - Assumptions Non-familiar work mode Must maintain cadence Leg fatigue • • • • Submaximal Prediction of CRF – Sources of Error Cycle Ergometer Protocols (other) HRmax Efficiency Calibration Accurate measurement of HR HR at steady state B/n HR of 110-150 HRmax = 220-age Steady State Constant cadence 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) 5 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 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 Treadmill Testing • Not usually used for submaximal testing • Range of efficiencies is so high • Would not recommend – but can be done 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) 6
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