JOURNAL OF WOMEN’S HEALTH & GENDER-BASED MEDICINE Volume 10, Number 9, 2001 Mary Ann Liebert, Inc. Applicability of Maximal Oxygen Consumption Criteria in Obese, Postmenopausal Women NOELLA A. MISQUITA, M.D., DAWN C. DAVIS, M.S., C. LYNNE DOBROVOLNY, M.S., ALICE S. RYAN, Ph.D., KAREN E. DENNIS, R.N., Ph.D., and BARBARA J. NICKLAS, Ph.D. ABSTRACT This study examines the applicability of using three standard criteria (age-predicted maximal heart rate [HRmax], respiratory exchange ratio [RER.1.10], and plateau in oxygen uptake [VO 2 ] for the measurement of maximal oxygen consumption (VO 2 max) in postmenopausal women. One hundred eight postmenopausal(60 6 6 years), overweight and obese (body mass index [BMI] 5 33 6 4 kg/m 2 ), sedentary (VO 2 max 5 19 6 3 ml/kg/min) women underwent one exercise test (Bruce protocol), and 71 of these women underwent a second test (modified Balke protocol). On test 1, 69 (64%) women achieved age-predicted HRmax, 61 (57%) reached an RER. 1.10, and 16 (15%) achieved a plateau in VO 2 ( , 2 ml/kg/min change). Women who reached age-predicted HRmax and reached an RER of at least 1.10 had a higher peak VO 2 (p, 0.01) than women who did not meet these criteria. There was no difference in the high- est VO2 obtained between women who did and did not achieve a plateau in VO 2 during test 1(p 5 0.55). Resting HR, HRmax, and RER were similar between the two tests. On average, peak VO 2 was higher on the second test (p, 0.01). However, VO 2 max was not different be- tween exercise tests in women who achieved at least two of the three criteria on both tests (n 5 24; test 1, 19.4 6 3.4; test 2: 19.8 6 3.7 ml/kg/min; p 5 NS). In addition, VO 2 max was sim- ilar between the two exercise tests in 14 women who reached a plateau on the second test but did not reach a plateau on the first test (19.2 6 3.3 vs. 19.6 6 4.2 ml/kg/min; p 5 NS). We con- clude that achievement of a plateau in VO 2 is not a necessary criterion for a valid measure- ment of VO 2 max in overweight and obese, sedentary, postmenopausal women. 879 INTRODUCTION M AXIMAL OXYGEN CONSUMPTION (VO 2 max) is a function of cardiac output and oxygen ex- traction from blood and is the most widely used index of cardiovascular fitness. 1,2 Because VO 2 max is an independent risk factor for cardio- vascular disease (CVD) and all-cause mortality, 3,4 its measurement is useful in quantifying CVD risk in older individuals. In addition, VO 2 max is a reliable measure of physical activity in terms of exercise training in older persons. 5 Determination Department of Medicine, Division of Gerontology, University of Maryland School of Medicine, and the Geriatric Research Education and Clinical Center (GRECC), Baltimore VA Medical Center, Baltimore, Maryland. This work was supported by the Department of Veterans Affairs Baltimore Geriatric Research Education and Clin- ical Center (N.A.M., B.J.N., K.E.D.), NIH grant R01 NR03514 (K.E.D., D.C.D., C.L.D.), NIH grant R29 AG14066-02 (B.J.N.), NIH grant K01 AG00747 (A.S.R.), NIA Research and Training in Gerontology and Exercise Physiology grant T32 AG002109 (N.A.M.), and the Claude Pepper Older Americans Independence Center (NIH/NIA-P60-AG12583).