Cardiorespiratory Fitness

Transcription

1 Cardiorespiratory Fitness Assessment Purpose Determine level of fitness & set goals Develop safe & effective exercise prescription Document improvements Motivation Provide info concerning health status Health Related Low levels d risk of premature death s reduction of death from all causes High levels high levels of PA & better health 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) Best Measure? VO 2max O 2 uptake Pulmonary O 2 transport Cardiac O 2 utilization - Muscular Measuring Cardiovascular Endurance (Aerobic Capacity) VO 2max Measure Estimate Laboratory Tests Field Tests 1

2 Laboratory Methods Measures of Maximal Exercise Capacity Maximal Oxygen Consumption Submaximal estimations Astrand Rhyming Nomogram YMCA Cycle Protocol Linear Relationships Among VO 2, HR. & Workload Field Methods Distance runs 1 Mile Run 1.5 Mile Run 12 Minute Run 6 Minute Walk Rockport 1-Mile Walk Test Field Methods Step tests YMCA 3-Minute Step Test Predicting VO 2max w/o exercise VO 2max = * self-reported physical activity.0289 * age in yrs & %Fat * gender Laboratory Tests Vs. Field Methods Advantages/Disadvantages?? (female = 0; male = 1) 2

3 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 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 VO 2 Field or Submaximal Tests disadvantages Maximum measures estimated VO 2max 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 (64-68 O ) air flow Assumptions of Submax Tests Measurements made in steady state Linear relationship b/n HR & VO 2 HR max 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 3

4 Indications for Stopping an Exercise Test in Low-Risk Adults 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 Criterion Based Reference Minimal levels of aerobic capacity associated with a reduced risk of disease & death Females = VO 2max of 31.5 ml/kg/min Males = VO 2max of 35.0 ml/kg/min Norm Based Reference 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 Tests Queens College or McArdle Step Test Step: ht = in for 3 min Men: 24 steps/min; Women: 22 steps/min Radial pulse in 1st-5 sec, for 15 sec Men: VO 2max = (0.42 * HR) Women: VO 2max = ( * HR) 1.5 Mile Run Record total time to complete 1.5 miles VO 2max = /time Time in nearest hundredth of min 4

5 12 Min Walk/Run Cover maximum distance in 12 min VO 2max = (3.126 * meters) 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 HR max = 220-age Steady State Constant cadence Submaximal Prediction of CRF Sources of Error HR max 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) 5

6 Cycle Ergometer Protocols (other) Astrand-Rhyming Cycle Ergometer Test (cont) 50 rpm Goal HR b/n 125 to 170 measured during 5 th & 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 VO 2max (ml/kg/min) = (body mass in kg) 0.39 (age in yrs) (gender) (time in min) 0.16 (HR) 1.5-mile run test VO 2max (ml/kg/min) = /(time in min) 6