Presentation on theme: "1 Graded Exercise Tests GXTs A multistage test that determines a person’s physiological responses to different intensities of exercise and/or the person’s."— Presentation transcript:
1 Graded Exercise Tests GXTs A multistage test that determines a person’s physiological responses to different intensities of exercise and/or the person’s peak aerobic capacity
2 When to use submaximal and maximal tests Evaluate CRF in fitness program for healthy population Load Heart Cardiovascular response Changes occur in ECG Clinical assessment of coronary heart disease Maximal test to determine the presence of CHD in asymptomatic individual Submaximal Evaluate cardiovascular fitness prior to and following a fitness program
3 Maximal GXT *a diagnostic, functional capacity test is mandatory for all people in the high-risk category who want to start an exercise program. * usually done with a treadmill or cycle ergometer Purposes of Maximal GXT with ECG To diagnose overt or latent heart disease To evaluate cardiorespiratory functional capacity To evaluate response to conditioning or cardiac-rehabilitation program To increase individual motivation for entering and adhering to exercise program
4 Maximal GXT Inactive person Discomfort from the test Discourage from participating in fitness program Submaximal GXT Find fewer abnormal responses Inaccurate estimate VO2max Suggestion: in a fitness program for apparently healthy people, administer submaximal test early and conduct a maximal test until the participant has been involved in a regular exercise program Your fitness center is responsible for both fitness program and fitness testing..
5 More about submaximal and maximal GXT Typically, Health/ fitness Instructor uses Sub- to estimate a person’s VO2max Predicted VO2max from any submaximal test involves error Only way to determine true functional capacity is to measure it during a maximal test Changes in HR, BP and RPE as a result of an exercise program make a submaximal test a good mechanism for showing improvements in CRF
6 Any of GXT protocols can be used for submaximal or maximal testing - the only difference is the criteria for stopping the test Test is stopped if any of the abnormal responses Absence of abnormal responses Submaximal when target HR reached often 85% of HRmax Maximal when a state of voluntary exhaustion reached
7 Guidelines for Exercise Test Administration Medical evaluation prior to testing medical history physical examination Contraindication to testing General principles of exercise testing Test protocols Informed consent Preparation for ECG monitoring Conducting the test Interpretation of the exercise test
8 Contraindications for Exercise and Exercise Testing P58 table 3.3
9 General principles of exercise testing 1. If there is any doubt as to the benefit of testing or the safety of testing, the test should not be performed at that time. 2. The test protocol should be selected to accommodate the individual patients ability to perform treadmill exercise or cycle ergometer. 3. The exercise test should begin at a MET level intensity considerably below the anticipated limitation or maximal capacity and increase gradually in 2- or 3-minute stages, with observation made at each different stage. The increase in intensity at each stage may be as large as 2 to 3 METs in healthy population or as small as 1/2 MET in those with disease.
10 4. Heart rate, blood pressure, rating of perceived exertion (RPE) and patient appearance and symptoms should be monitored regularly. 5. Contraindications for testing and indication for stopping exercise should be closely observed. 6. All observations should be continued for at least 4 minutes on recovery unless abnormal responses occur which would require a longer post-test observation. 7. The testing area should be 22C (72F)or less and the humidity 60% or less if possible.
12 Maximal Exercise Test Protocols No one GXT protocol is appropriate for all types of people Young active Sedentary Questionable health status Start 6 METs 4 METs 2 METs Increment 2-3 METs 1-2 METs 0.5-1 METs per stage Time per stage 1-2 minutes 2-3 minutes Compare CRF Predict VO2max
13 Testing Protocol for Different Groups P 220 T 11.6
14 Submaximal Treadmill Test Protocols Balke Standard Protocol 3.5 mph, 2.5% grade increase every 2 minutes Heart rate monitored in the last 30s of each stage Test terminated at 85% of age-adjusted maximal heart rate Maximal aerobic power estimated by extrapolating the HR response to the person’s estimated maximal heart rate The heart rate response is usually quite linear between 110 beats/min and the subject’s 85% of maximal HR cutoff
15 Submaximal Cycle Ergometer Test Protocols p223
16 Submaximal Cycle Ergometer Test Protocols A linear relationship between HR and work rate (VO2) once a HR of approximately 110 beats/min is reached The subject is required to complete one more stage past the one causing HR of 110 beats/min Each stage lasts 3 minutes, unless a subject’s HR has not reached a steady state (greater than 5 beats/min difference between 2nd and 3rd-min HR). In that case, an extra minute is added to that stage the pedal rate is maintained at 50 rev/min, so that, on a Monark cycle, a 0.5-kp increase in load is equal to 150 kpm/min (25W) 50 rev/min X 6 meters/rev X 1 kp = 300 kg.m/min 1 watt = 6.0 kg.m/min 1 kp = I kilopond = kilogram
17 Submaximal Cycle Ergometer Test Protocols Seat height is adjusted so that the knee is slightly bent (5 0 ) when the pedal is at the bottom of the swing through 1 revolution seat height is recorded HR is monitored during the later half of the 2nd and 3rd min of each stage
18 Guide for setting workloads for men and women on YMCA submaximal cycle ergometer test P224 f 11.4
19 A sample of YMCA submaximal cycle ergometer test P224 correction factor p225 f11.5 and In review