Cardiorespiratory Testing

Maximal Oxygen Uptake . AKA VO2 Max Criterion measure of cardiorespiratory fitness Product of maximal cardiac output and arterial-venous oxygen difference Directly related to functional capacity of the heart

Maximal Oxygen Uptake Direct measurement Open-circuit spirometry Pulmonary ventilation Expired O2 and CO2 fractions

Maximal Oxygen Uptake . . Indirect methods Estimation techniques VO2 values correlated with intensities reached Similarities in fitness levels Similarities in age and gender Regression equations used to predict VO2 . .

Maximal Oxygen Uptake Indirect methods Estimation techniques Step tests Little equipment or skill needed Short duration test – less than 5 minutes Requires some balance Difficult for extremely deconditioned

Maximal Oxygen Uptake Indirect methods Estimation techniques Field tests – practical (mass testing) Cooper 12 minute run Requires maximal effort & motivation Unmonitored – danger for at-risk? Rockport 1 mile walk Unmonitored but walking vs. running decreases danger

Maximal Oxygen Uptake Indirect methods Estimation techniques Treadmill tests Accommodates all fitness levels – speed changes Requires skill and balance for some – practice? Difficult to measure BP

Maximal Oxygen Uptake Indirect methods Estimation techniques Cycle ergometer tests Easy to take BP measurements Non weight bearing – accommodates extremely weak Small work rate adjustments can be made Familiar skill – but not a common activity Severe localized fatigue - motivation Specific pedal cadence is required - motivation

Maximal Oxygen Uptake Maximal Exercise Tests Advantage Disadvantage True maximal capacity can be measured Increased sensitivity in Dx of CAD in asymptomatic Disadvantage Volitional fatigue do they know maximum? risk of injury Physician supervision* Emergency equipment*

Maximal Oxygen Uptake Maximal Exercise Tests Incremental workloads Steady state not required “Quick and dirty” Just max is the goal Prolonged – other measures along the way Ventilatory threshold Lactate threshold

Maximal Oxygen Uptake Submaximal Exercise Tests Assumptions Steady is state reached at each work rate Linear relationship between HR and work rate Maximal HR is uniform for every age Predict max from slope of line

Submaximal Testing Keys to success 2-3 min warm-up and equipment acquaintance Monitor HR & BP near the end of each stage Perceived exertion (6-20 or 1-10 scale) Monitor subject’s/client’s appearance Terminate at 85% of age-predicted max HR, or 70% of HR reserve, or if problems arise Allow warm-down & monitor

Submaximal Testing Test Termination Criteria in Low-risk adults (Box 4-5) ***Subject requests to stop*** **Failure of testing equipment** Onset of angina – pain associated with ischemia Significant rise or drop in BP Signs of poor perfusion – pallor Failure of HR to increase with workload increase Noticeable change in heart rhythm Severe fatigue

Submaximal Testing . . Cycle Ergometer Tests Astrand-Rhyming Cycle Ergometer Test (page 70) Single stage test – target HR from 125-170 Work Rate – (@ 50 rpm) Men – unfit 300 or 600, fit 600 or 900 kgm/min Women – unfit 300 or 450, fit 450 or 600 kgm/min Heart rate taken @ 5th & 6th min. – average them Use of nomogram to estimate max VO2 (Figure 4-1) Correct VO2 max by multiplying correction factor for age difference in max HR . .

Submaximal Testing . . Cycle Ergometer Tests YMCA Cycle Ergometry Test (page 74) 2 - 4 stage continuous exercise Branching – if ___ Hr, then ___ intensity Heart rate taken @ 2nd & 3rd min. of each stage HR must be within 6 beats to go to next stage HR must be between 110 and 85% age predicted max Plot HRs of last min. then extrapolate to max HR Line to predicted work rate at max VO2 Calculate a predicted VO2 (Appendix D) . .

Prediction Line Max HR 220-age Submax 2 Submax 1 Max Work Rate

Evaluation of Results . Compare predicted VO2 to norm table (table 4-8)

Example Male, Age = 45 1st stage yields HR of 98 2nd stage yields HR of 121 3rd stage yields HR of 143 Age predicted max HR = 175 85% of max HR = 149 Predicted max = ? Plot to find

Example . Use graph to plot predicted work rate at max HR Used predicted max work rate for calculation of predicted max VO2 .

Maximal Testing Purpose Physician Supervised? Diagnosis of CAD Prognosis of client regarding disease Finding functional capacity for prescription (CRF – Cardiorespiratory Function) Physician Supervised? Low risk & men < 45 yr / women < 55 yr Moderate & High risk

Maximal Testing Personnel “Experienced paramedical personnel” ACSM Exercise Specialist Certified? KSA’s Exercise Physiology and Related Exercise Science Pathophysiology and Risk Factors Health Appraisal, Fitness and Clinical Exercise Testing Electrocardiography and Diagnostic Techniques Patient Management and Medications Medical and Surgical Management Exercise Prescription and Programming Nutrition and Weight Management Human Behavior and Counseling Safety, injury Prevention, and Emergency Procedures Program Administration, Quality Assurance, and Outcome Assessment

Maximal Testing Work Rate Changes Incremental Format Ramp Format 1 minute – 3 minutes Large intensity changes Time to reach steady state Ramp Format ~ 20 sec stages Small intensity changes Smoother – non-steady state

Maximal Testing Clinical Treadmill Bruce Protocol most common large metabolic demand increments best for more fit subjects 3 min stages increases in speed & grade

Maximal Testing Clinical Treadmill Balke-Ware small work increments best for less fit subjects 1 min stages speed remains at 3.3 mph increases in grade only by 1% each stage

Maximal Testing Sequence of Measures HR (ECG), BP, RPE, Familiarization, Termination Box 4-4 Pre Exercise Posttest

Maximal Testing Indications for Terminating Test Absolute Relative Decreased medical status Equipment Failure Request to stop Relative Change in hemodynamic function Change in ECG Fatigue / Chest Pain

Maximal Testing Symptomatic Angina Scale 1+ Light, barely noticeable 2+ Moderate, bothersome 3+ Moderately severe, very uncomfortable 4+ Most severe or intense pain ever experienced A 3+ would indicate stopping a test

Maximal Testing . . . Functional Aerobic Impairment %FAI = (Predicted VO2 – Observed VO2) x 100 Predicted VO2 . . .

Maximal Testing . . Metabolic Equivalents – METs Multiples of VO2 at rest - 3.5 ml/kg/min Predicted average max VO2 in METs Men= (57.5 - .445 x age) / 3.5 Women= (42.3 - .356 x age) / 3.5 . .

Maximal Testing Performance Determine functional capacity Velocity at max for prescription and program assessment HR at max for prescription and program assessment Power at max for prescription and program assessment

Maximal Testing Performance Methods Max only “Quick & dirty” – rapid rise in intensity until max 8- 12 minutes of testing No need for steady state max is goal without fatigue from time

Maximal Testing Treadmill Protocol Ramp or incremental stages Alternate speed and / or grade Limitation should be physiological not psychological

Maximal Testing Cycle Ergometer Protocol Ramp or incremental stages Maintain pedal cadence Increase tension Seated & legs only – no standing or arm assistance Limitation should be physiological not psychological

Maximal Testing . . Max VO2 Determination Criteria Caveat 1. Use of large muscle groups Caveat 2. Activity specific to “athlete’s” sport No increase in VO2 with increase in work rate RER > 1.15 HR during final stage + 10 beats of predicted HR * Blood lactate concentration > 8 mmoles/liter .

Max VO2 VO2 (ml/kg/min) . Work Rate

Maximal Testing . . . PEAK VO2 Highest VO2 reached without meeting caveats Highest VO2 reached without meeting 2 of 3 criteria . .

Maximal Testing Threshold Determination OBLA – rapid blood lactate accumulation T-vent - non-linear ventilation increase Protocol Smaller intensity increments – not too small! Even intensity increments Minute by minute measures – “catch” the inflection point May last too long to achieve max (fatigue)

Ventilatory Threshold Ventilation (ml/min) T-vent Work Rate

Supra-maximal Testing Wingate Anaerobic Power Test Energy supply beyond aerobic metabolism Protocol Cycle ergometer 30 second ride at maximal cadence Load = 7.5% to 10% of body mass (kg) Determines peak power (watts) Determines average power Determines %Power Decline

Supra-maximal Testing Wingate Anaerobic Power Test Indices Phosphagen stores Glycolytic system Buffering capacity Motivation & capacity to tolerate discomfort “Kick” at the end of a race or surge during the race Power to weight ratio (relative power)

Questions?

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