This page intentionally left blank
MMMM
Exercise testing and interpretation A practical approach
In Exercise Testing and Interpretation: A Practical Approach, Approach , Drs Christopher Cooper and Thomas Storer o V er er a practical and systematic systematic approach to the acquisitio acquisition, n, interpret interpretation ation,, and reporting of physiologic responses to exercise. Pulmonolo Pulmonologists gists,, cardiolo cardiologists gists,, and sports sports physicians physicians,, as well as respiratory therapists and other allied health professionals, will
Wnd
this book an indispensable resource when
learning to select proper instruments, identify the most appropriate test protocols, and integrate and interpret physiologic logic response response variables. variables. The
Wnal
chapter chapter presents presents clinical clinical
cases to illuminate useful strategies for exercise testing and interpretation. Useful appendices oV er er answers to frequently asked questions, laboratory forms, algorithms, and calculations, tions, and a glossa glossary ry of terms, terms, symbols symbols,, and de Wnitions. Exercise Testing and Interpretation: A Practical Approach offers clearly deWned responses (both normal and abnormal) to over over 40 perfor performan mance ce variab variables les includ including ing aerob aerobic, ic, carcardiovascular, ventilatory, and gas exchange variables. Practical, portable, and easy-to-read, this essential guidebook can be used as a complement to more detailed books on the topic, or stand on its own.
Christopher Cooper is Professo Professorr of Medicine Medicine and Physiolog Physiology y at the UCLA School of Medicine and Medical Director of the Exercise Physiology Laboratories at the UCLA Medical Center. Dr. Cooper is a Fellow of the American College of Chest Physician Physicians, s, Royal Royal College College of Physicians Physicians,, and the American American Colleg College e of Sports Sports Medici Medicine. ne. He has author authored ed severa severall research search public publicati ations ons,, review reviews, s, and book book chapte chapters rs on the topics of exercise physiology and
Wtness,
chronic obstructive
pulmonary pulmonary disease, disease, pulmonary pulmonary rehabilit rehabilitation ation,, and oxygen oxygen therapy.
Thomas Thomas W. Storer Storer establishe established d the Exercise Exercise Science Science LaboraLaboratory tory progra programs ms for for exerci exercise se physio physiolog logy y and
tnesss Wtnes
at El
Camino Camino College in 1979 and is now Professor, Professor, Division Division of Health Health Sciences Sciences and Athletics Athletics at El Camino Camino College, College, serves as Director of the Exercise Science Laboratories and Pulmonary Exercise and Education Program at El Camino, and holds an appointment appointment in the Department Department of Medicine Medicine at Charles Charles R. Drew University of Medicine and Science in Los Angeles. He also teaches teaches graduate graduate and undergraduate undergraduate exercise physiology and community Wtness tness at El Camino Camino College College and was the 1998–99 recipient of their Distinguished Faculty Award.
MMMM
MMMM
MMMM
Exercise testing and interpretation A practical approach Christopher B. Cooper University of California Los Angeles
Thomas W. Storer El Camino College
The Pitt Building, Trumpington Street, Cambridge, United Kingdom
The Edinburgh Building, Cambridge CB2 2RU, UK 40 West 20th Street, New York, NY 10011-4211, USA 477 Williamstown Road, Port Melbourne, VIC 3207, Australia Ruiz de Alarcón 13, 28014 Madrid, Spain Dock House, The Waterfront, Cape Town 8001, South Africa http://www.cambridge.org © Christopher B. Cooper and Thomas W. Storer 2004 First published in printed format ISBN 0-511-03616-7 eBook (Adobe Reader) ISBN 0-521-64050-4 hardback ISBN 0-521-64842-4 paperback
Dedicated to Nancy and Paula
MMMM
‘‘Those who do not make time for exercise will eventually have to make time for illness’’ The Earl of Derby (1863)
MMMM
MMMM
Contents
Preface
ix
1 Purp Purpos ose e
1
2 Instrume Instrumentat ntation ion
15
3 Testi Testing ng me metho thods ds
51
4 Response Response variables variables
93
5 Data integrat integration ion and interpret interpretation ation
149
6 Illustrat Illustrative ive cases cases and and repor reports ts
181
Appendix A Glossary (terms, (terms, symbols, deWnitions) Appendix B Calculations and and conversions Appendix Appendix C Reference Reference values Appendix D Protocols and supplemental materials Appendix E Frequently asked questions Index
204 211 220 241 261 265
vii
MMMM
MMMM
Preface
Exercise is fundamental to human existence. For most men and and women exercise exercise is essenti essential al for quality of life and for many it is the essence of their liveli livelihoo hood.Some d.Some have have a compet competiti itive ve instin instinct ct for athathletic performance in the pursuit of individual human achiev achieveme ement. nt. We now unders understan tand d that that the maintenance of physical Wtness throughout life is crucial if we are to remain healthy and live to an advanced advanced age. In these contexts, contexts, the assessme assessment nt of exercise ability is of considerable importance to humanity. Exercise testing becomes the means of assessing ability to perform speci Wc tasks, quanti Wcation cation of athlet athletic ic perfor performan mance, ce, diagn diagnosi osiss of diseas disease, e, assess assessmen mentt of disabi disabilit lity, y, and evalua evaluatio tion n of responses to physical training, therapeutic intervention, and rehabilitation. Recent years have indeed witnessed widespread applic applicati ations ons of exerci exercise se testin testing g that that range range from from clinical clinical uses in assessin assessing g debilita debilitated ted patients patients to sports medicine medic ine venues venue s and the testing t esting of o f e´lite ´lit e athletes. letes. Some exercise tests are appropriat appropriately ely performed with a minimum of equipment, such as a watch and a measured course. Others involve more sophistic sophisticated ated instrumen instrumentati tation on enabling enabling more detailed tailed assessme assessments. nts. Advances Advances in technolog technology y have render rendered ed all exerci exercise se tests tests more more access accessibl ible e and more aV ordable, ordable, although not necessarily easier to perfor perform m with with accura accuracy cy and reliab reliabili ility. ty. Wirele Wireless ss heart rate monitors give instantaneous and reliable heart heart rates rates in the the Weld or in the laboratory laboratory.. Bi-direcBi-directional, tional, light-weig light-weight, ht, mass Xow sensor sensorss have have obviated the need for cumbersome valves and tubing and, together with miniaturized and fast-responding gas analyz analyzers, ers, enable enable the calcula calculation tion of oxygen oxygen uptake uptake with with every every breath breath.. Comput Computer er techno technolog logy y has
ix
x
Preface
revolutionized the real-time acquisition and analysis of data, although not necessarily made exercise tests any easier to interpret. We have both practiced and taught in the Weld of exercise testing and interpretation for many years. We saw the need for a practical text that succinctly explains the physiology of exercise and also gives detailed detailed advice advice regarding regarding the conduct conduct and interpreinterpretation of exercise tests in a variety of settings. We have included clinical and sports medicine medicine applications because we are convinced that these disciplines will merge in the future. We have addressed technical considerations, considerations, pitfalls, and solutions. We have placed emphasis on creative Wgures and diagrams to oV er e r syst system emat atic ic expl explan anat atio ions ns and and schemata for interpretation. We have also attempted to address address the confusion confusion that surrounds surrounds termiterminology nol ogy in this this divers diverse e Weld. eld. We have have done done so through a systematic, logical, and critical examination of the concepts and applications of the Weld. We hope our approach is enlightening and not a mere addition to the plethora of terms and symbols already in use. which h we abbr abbrev evia iateto teto XT, XT, can can be Exercise Exercise testing testing , whic conducted for several purposes, in a variety of settings. Performance exercise tests (PXT) can be performed formed in the the Weld using a selection selection of Weld or laboratory using protocols, depending upon the purpose of the test. Typicaly, PXT are conducted to establish exercisetraining guidelines and to monitor progress. Clinierent cal exercise tests (CXT) have a somewhat di V erent emphasis emphasis and are almost almost exclusiv exclusively ely conduct conducted ed in a laboratory setting. CXT can be diagnostic , seeking an explanation for exercise impairment; for risk assessment , such as from coronary artery disease or surgery; surgery; or alternative alternatively ly for monitoring , for for exam exampl ple e to quantify the response to therapeutic or surgical interventi interventions onsor or to document document progress progress in rehabilit rehabilitaation. tion. Exerci Exercise se capaci capacity ty can be measur measured ed by diV erent erent protocols ranging from the time required to complete plete a measur measured ed course course to the acquis acquisiti ition on of a wide wide range of cardiova cardiovascula scular, r, ventilatory, ventilatory, and gas exchange variables. Functional exercise tests focus on ability ability to perform perform a speciWc task task wherea whereass integrative exercise exercise tests compile compile an array of variables variables with
which to study the underlying physiology of the exercise response. Several features of this book are unique. The core of the book describes instrumentation and protocols for exercise testing followed by response variables and their interpretation. The book is laid out so that the reader can easily locate locate a piece of equipment ment or respon response se variab variable le for ready ready refere reference nce.. Chapter Chapter 2 (Instrumen (Instrumentati tation) on) describes describes apparatus apparatus for exercise testing explaining, succinctly, the principles ciples of operat operationand ionand essent essential ial facts facts about about calibr calibraation and maintenance of the equipment. Chapter 3 (Testing methods) describes protocols for exercise testing with many important details, gleaned from years of experience, that facilitate a successful test. Chapte Chapterr 4 (Respo (Response nse variab variables les)) expand expandss on the many physiological variables that can be derived from exercise testing, ranging from simple timed distances to the complex integrated cardiovascular and gas exchan exchange ge variab variables les which which underl underlie ie the exerexercise cise respon response. se. Each variab variable le has its own sectio section n incl includ udin ing g a deWnition nition,, deriva derivatio tion, n, and units units of measurement, along with examples of the normal and abnormal responses. Chapter 5 (Data integration and interpretation) presents a novel and systemati tematic c approa approach ch to help help the reader reader develo develop p a conWdent dent and meanin meaningfu gfull interp interpret retati ation on of the data. data. There is an emphasis here here on integrative integrative exercise testing testing because because interpreta interpretation tion of this type of XT XT has often presented more problems to the exercise practitioner. Chapter 6 illustrates the principles expounde pounded d in Chapte Chapters rs 2 through through 5 with a select selection ion of real cases. Finally, the appendices are designed to be a valuable resource for the exercise practitioner. They include a glossary of proper terms and symbols bols as adopte adopted d by exerci exercise se physio physiolog logist ists, s, simpli simpliWed algorithms to help explain the derivation of secondary ondary variab variables les,, predic predicted ted normal normal values values with with appropriate critique, examples of worksheets that facilitate testing, and a section on frequently asked questions. Finally, a few words about the units of measurement incorporated in this book. Our goal has been to write a book that will be of practical value to persons throughout the world who are involved in
Preface
exercise exercise testing testing and interpreta interpretation. tion. As such we have had to deal deal with with certai certain n incons inconsist istenc encies ies in curren currently tly accepted accepted units units of measureme measurement. nt. Some countries, countries, including the USA, continue to use imperial rather than metric units for certain measurements. The attempts to bring bring Syste `me International d’Unite´s ´s attempts everyone into concordance with a metric system. However, some traditional units do not lend themselves selves comfor comfortab tably ly to this this conver conversio sion. n. We have have used used SI units units wherev wherever er possi possible ble but referr referred ed to tradit tradition ional al units as well when conversion was not straightfor ward. Readers will undoubtedly Wnd some inconsistencie sistenciess and discrepanc discrepancies ies but hopefully hopefully these can always be resolved by reference reference to Table B1 in Appendix B which explains any necessary conversions. This book is intended to be a practical text which exercise practitioners would want readily available in their clinical or research laboratories, rehabilitation tion facili facilitie ties, s, and sports sports clubs. clubs. The book book may prove prove useful for chest physicians, cardiologists, exercise physio physiolog logis ists, ts, occupa occupatio tional nal health health physic physician ians, s,
Acknowlegments This book has evolved from what we have learnt from our mentors, mentors, students students,, and patients. patients. However, However, its production owes much to the support of others. We wish to thank the staV at Cambridge University Press, particularly Jocelyn Foster who was involved at the conception of the project and Liz Graham who undertook the formidable task of copyediting. We are especi especiall ally y indebt indebted ed to Judy Judy Valesq Valesquez uez for her meticulous preparation of the Wgures. Finally, we must acknowledge our families for accepting the many hours we were not with them. CBC, TWS
sports sports physician physicians, s, sports sports scientist scientists, s, laboratory laboratory technicians, physical or respiratory therapists, medical students, and postgraduate postgraduate students in the exercise scienc sciences. es. The materi material al for the book book has evolve evolved d over over many years of teaching exercise physiology, exercise testing, and interpretation. Parts of the book reXect a syllabus that we have developed and rened over over the the past past eigh eightt year yearss for for an annu annual al symp sympooWned sium that that has taken taken place at UCLA UCLA as well as several several national and international venues. Re Xecting our own careers and experiences, we have tried to approach the topic simultaneously from the perspectives of exercise science and clinical medicine. By doing so we have attempted to develop a comprehensive and balanced view of a complex subject which we hope will appeal to, and draw together, a broad range of disciplines with a common purpose – that that of unders understan tandin ding g the human human exerci exercise se response. CBC, TWS Los Angeles, California
xi
1 Purpose
Introduction The human human body is design designed ed for the perfor performan mance ce of exercise. Habitual patterns of exercise activity are known known to be linked linked to healt health, h, well-b well-bein eing, g, and risk risk of disease disease.. In Wtness and athletics, exercise capacity is linked to performance and achievement. In clinical medicine, medicine, exercise performan performance ce is intricate intricately ly related lated to functi functiona onall capaci capacity ty and qualit qualityy of life. life. Hence the importance of exercise testing and interpretat pretationas ionas a means means of determ determini ining ng exerci exercise se capaccapacity ity and and iden identi tify fyin ingg fact factor orss whic which h migh mightt limi limitt exerci exercise se perfor performan mance. ce. Exerci Exercise se profes professio sional nals, s, whether concerned with physical physical Wtness and sports or clinical medicine and rehabilitation, should be well well versed versed in method methodss of exercis exercisee testin testingg and interinterpretation. Hence the need for a practical guide to assist in this undertaking. A wide variety of methods have evolved for the purpose of assessing exercise capacity and identifying ifying speci speciWc limi limiti ting ng fact factor ors. s. Fiel Field d test testss are are commonly used in Wtness and sports to assess athletic performanc performance, e, but can be used to assess progress in clinical or rehabilitative settings. Laboratory exercis exercisee protoc protocolsare olsare also also used used to assess assess Wtness tness and are often combined with electrocardiography electrocardiography to diagnose coronary artery disease. Symptom-limited, incrementa incrementall exercise exercise testing, testing, including including measuremeasurement ment of vent ventil ilat atio ion n and and gas gas exch exchan ange ge,, has has prov proven en to be an important diagnostic, clinical, prescriptive, and rehabi rehabilit litati ative ve tool. tool. These These more more comple complexx labora labora-tory tests evaluate the integrated human cardiovascular, cular, ventilator ventilatory, y, and musculoske musculoskeletal letal responses responses to
exercise. Whether the assessment is conducted in the Weld or in the laboratory, all of these exercise tests tests requir requiree carefu carefull attent attentionto ionto detail detailif if meanin meaningfu gfull information is to be derived. This book provides a detailed examination of the instruments, methods, proper conduct, and interpretation of a variety of exercise tests. tests. This is meant to be a practical guide, assisting the reader in every step of the process with fundamental information, exampl examples, es,and and practi practice ce using using a time-t time-test ested ed method method-ology. ology. The next section of this chapter chapter reviews the basic exercise physiology physiology that underlies underlies exercise exercise testing and interpretation. It is included not as a primer, but rather to illustrate the important concepts involved.
Basic exercise physiology Coupling Coupling of cellular cellular respiration respiration to external external work
During During the performance performance of most types of exercise, exercise, it is well known that oxygen uptake (V o2) is tightly ˙ ) or power output. coupled to external work rate (W (W The essential essential components of this coupling are illusillustrated trated in Figure Figure 1.1. Central Central to our understan understanding ding of exercise physiology is the measurement of alveolar oxygen uptake (V o2alv ) by collection and analysis of exhaled gases. V o2alv provides the systemic arterial oxygen oxygen content content for delivery delivery to exercising exercising muscles. Hence, the extent to which V o2alv matches muscle ˙ o2mus) is in part a re Xection oxygen consumption (Q (Q of the eV ective ectivenes nesss of oxygen oxygen delive delivery ry via the ˙
˙
˙
˙
1
