Relationship between maximum aerobic power and resting metabolic
rate in young adult females.
Smith, D. A., J. Dollman, R. T. Withers, M. Brinkman, J. P. Keeves, D.
G. Clark.
Exercise Physiology Laboratory, School of Education, The Flinders
University of South Australia, GPO Box 2100, Adelaide, South
Australia 5001, Energy Metabolism Laboratory, CSIRO (Australia),
Division of Human Nutrition, PO Box 10041, Gouger Street, Adelaide,
South Australia 5000
APStracts 3:0401A, 1996.
The literature is inconclusive as to the chronic effect of aerobic
exercise on resting metabolic rate (RMR) and furthermore there is a
scarcity of data on young females. Thirty-four young females
exhibiting a wide range of aerobic fitness (O2max=32.3-64.8 ml.kg
-1.min-1) were accordingly measured for: RMR by the Douglas bag
method, treadmill O2max and fat free mass (FFM) using Siri's three
compartment model. The interclass correlation (n = 34) between RMR
(kJ.h-1) and O2max (ml.kg-1.min-1) was significant (r = 0.39,
p<0.05). However, this relationship lost statistical
significance when RMR was indexed to FFM and when partial correlation
analysis was used to control for FFM differences. Furthermore,
multiple linear regression analysis indicated that only FFM emerged
as a significant predictor of RMR (kJ.h-1). When high (n = 12) and
low (n = 12) fitness groups were extracted from the cohort on the
basis of O2max scores, independent t tests revealed significant
between group differences (p<0.05) for RMR (kJ.kg-1.h-1) and
O2max (ml.kg-1.min-1) but not for RMR (kJ.h-1), RMR (kJ.kg FFM-1.h-1)
and FFM. Analysis of covariance of RMR (kJ.h-1) with FFM as the
covariate also showed no significant difference (p=0.56) between high
and low fitness groups. Thus the results suggest that: (1) FFM
accounts for most of the differences in RMR between subjects of
varying maximum aerobic powers and (2) the RMR per unit of FFM in
young healthy women is unrelated to O2max.
Received 26 April 1995; accepted in final form 26 August 1996.
APS Manuscript Number A452-5.
Article publication pending Journal of Applied Physiology.
ISSN 1080-4757 Copyright 1996 The American Physiological Society.
Published in APStracts on 19 September 1996