Chapter 15: Work Tests to Evaluate Cardiorespiratory Fitness

Chapter 15:Work Tests to Evaluate Cardiorespiratory Fitness EXERCISE PHYSIOLOGY Theory and Application to Fitness and Performance, 5th edition Scott K. Powers & Edward T. Howley Presentation revised and updated by TK Koesterer, Ph.D., ATC Humboldt State University

Objectives 1. Identify sequence of steps in the procedures for evaluating cardiorespiratory fitness (CRF) 2. Describe one maximal and one submaximal field test used to evaluate CRF 3. Expalin the rationale underlying the use of distance runs as estimates of CRF 4. Identify commom measures taken during a graded exercise test (GXT) 5. Describe changes in the ECG that may take place during a GXT in subjects with ischemic heart disease

Objectives 6. List three criteria for having achieved VO2 MAX 7. Estimate VO2 MAX from the protocol that may affect that estimate 8. Estimate VO2 MAX by extrapolating the HR/ VO2 relationship to the person#s age-adjusted maximal HR 9. Describe the problems with the assumptions made in the extrapolation procedure, and name the environmental and subject variables that must be controlled to improve such estimates

Objectives 10. Identify criteria used to terminate the GXT 11. Explain why there are so many different GXT protocols and why the rate of progression through the test is of concern 12. Describe the YMCA‘s procedure to set the rate of progression on a cycle ergometer test 13. Estimate VO2 MAX with the Åstrand and Ryhming nomogram given a data set for the cycle ergometer or step

Testing Procedures • Sign consent form • Screening • PAR-Q • Resting and exercise measures • HR & BP • Cholesterol • ECG • GXT or field test

Decision Tree in the Evaluation of Cardiorespiratory Fitness Fig 15.1

Field Tests for Estimating Cardiorespiratory Fitness • Use natural activities • Walking, running, or stepping • Can test large numbers of people at low cost • Physiological responses may be difficult to measure • Motivation plays an important role in test results

Maximal Run Tests • Measure how far a person can run in a set time or how fast they can run a set distance • Cooper’s 12-minute run and 1.5 mile run • AAPHERD’s 1-mile run/walk • VO2max estimates based on the linear relationship between running speed and oxygen cost of running

Walk Tests • Requires only simple measurements • Walking time • HR • VO2max is based on: • Age, weight, sex, time, and HR • As fitness improves, HR and/or time will be lower • Results in higher estimated VO2max

Canadian Home Fitness Test • Uses 8-inch steps to evaluate cardiorespiratory fitness • Measure HR after 3 minutes of stepping • Stop if it exceeds maximum allowable HR based on age • Continue for another 3 minutes if it is below maximum allowable HR • Fitness level is based on post-exercise HR

Graded Exercise Tests:Measurements • Heart rate • By palpation, ECG, or monitor • Blood pressure • By auscultation • ECG • Can diagnose arrhythmias or ischemia • Rating of perceived exertion (RPE) • Subjective measure of fatigue • ACSM guidelines

GXT:Termination Criteria ACSM’s Guidelines for Exercise Testing & Prescription • Onset of angina (chest pain) • Drop in systolic BP with increasing work rate • Excessive rise in BP (>260/115 mmHg) • Dizziness, ataxia, confusion, pallor • Failure of HR to rise with work rate • Noticeable change in heart rhythm • Subject requests to stop • Severe fatigue • Failure of testing equipment

VO2 MAX • The gold standard measure of cardiorespiratory fitness • Estimation from last work rate • Use equations to calculate estimated VO2max • Estimation from submaximal heart rate • Extrapolate measured submaximal HR to age-predicted maximal HR to estimate VO2max • Careful measurement of HR is required

Estimation of VO2max From Submaximal HR Response • The test is stopped when the subject reaches 85% of maximal HR • A line is drawn through the HR points measured during the test and is extrapolated to the age-adjusted estimate of maximal HR • Another line is dropped down from that point to the x-axis, and the VO2max is identified

Estimation of VO2 MAX From Submaximal Cycle Ergometer Test Fig 15.4

Graded Exercise Test: Protocols • Consideration of the population tested • Submaximal vs. maximal test • Starting work rate • Rate of change of work rate • Mode of exercise • Treadmill • Cycle ergometer • Step test

Treadmill • Use natural activities • Walking and running • Can accommodate a wide range of subjects • Least fit to most fit • Estimating VO2max • Based on extrapolating submaximal HR

Estimation of VO2max From a Submaximal Treadmill Test Fig 15.1

Cycle Ergometer • Body weight is supported • Can accommodate subjects with orthopedic limitations • Estimating VO2max • Based on extrapolating submaximal HR • YMCA protocol

Example of the YMCA Protocol Used to Estimate VO2 MAX Fig 15.7

The Y’s Way to Physical Fitness Cycle Ergometer Protocol Fig 15.6

Step Test • Simple, inexpensive equipment • Protocols differ in: • Step height • Step rate • Estimating VO2max • Based on extrapolating submaximal HR

Predicting VO2max From Submaximal Step Test Fig 15.9

Chapter 15: Work Tests to Evaluate Cardiorespiratory Fitness