title: Changes in aerobic power of women, ages 20-64 yr.
abstract: This study quantified and compared the cross-sectional and longitudinal influence of age, self-report physical activity (SR-PA), and body composition (%fat) on the decline of maximal aerobic power (VO2peak) of women. The cross-sectional sample consisted of 409 healthy women, ages 20-64 yr. The 43 women of the longitudinal sample were from the same population and examined twice, the mean time between tests was 3.7 (+/-2.2) yr. Peak oxygen uptake was determined by indirect calorimetry during a maximal treadmill test. The zero-order correlation of -0.742 between VO2peak and %fat was significantly (P < 0.05) higher then the SR-PA (r = 0.626) and age correlations (r = -0.633). Linear regression defined the cross-sectional age-related decline in VO2peak at 0.537 ml.kg-1.min-1.yr-1. Multiple regression analysis (R = 0.851) showed that adding %fat and SR-PA and their interaction to the regression model reduced the age regression weight of -0.537, to -0.265 ml.kg-1.min-1.yr-1. Statistically controlling for time differences between tests, general linear models analysis showed that longitudinal changes in aerobic power were due to independent changes in %fat and SR-PA, confirming the cross-sectional results. These findings are consistent with men's data from the same lab showing that about 50% of the cross-sectional age-related decline in VO2peak was due to %fat and SR-PA.
authors.affiliation: Cardiopulmonary Laboratory, Kelsey-Seybold Clinic, NASA/Johnson Space Center, Houston, TX 77058, USA. ajackson@jetson.uh.edu
authors.forename: A S
authors.initials: AS
authors.lastname: Jackson
authors.forename: L T
authors.initials: LT
authors.lastname: Wier
authors.forename: G W
authors.initials: GW
authors.lastname: Ayers
authors.forename: E F
authors.initials: EF
authors.lastname: Beard
authors.forename: J E
authors.initials: JE
authors.lastname: Stuteville
authors.forename: S N
authors.initials: SN
authors.lastname: Blair
mesh_terms: D000328:Adult; D000375:Aging / Q000502:physiology*; D001823:Body Composition; D003430:Cross-Sectional Studies; D015444:Exercise / Q000502:physiology*; D005260:Female; D006801:Humans; D008137:Longitudinal Studies; D008875:Middle Aged; D010101:Oxygen Consumption; D010809:Physical Fitness; D012044:Regression Analysis