Exercise training lowers the resting metabolic rate of Zebra Finches, Taeniopygia guttata

Abstract

1. Although changes in the mass and biochemistry of vertebrate locomotory muscle are established responses to exercise training, the effects of training on resting metabolic rate (RMR) are not clear. Here, a sustained flight training regime was shown to lower both the night-time and day RMR of captive Zebra Finches (Taeniopygia guttata). Training also reduced fat reserves and overall body mass. 2. Our results are largely consistent with the effects of an elevated energy expenditure on night-time RMR detected in a study of workload on Zebra Finches but contrast with most studies of humans, where exercise training increases or has no effect upon RMR. 3. A compensatory lowering of RMR in response to increased physical activity may be an artefact of captivity and could be dependent upon the activity levels of the captives concerned. 4. It is suggested that when extrapolating from cage bird studies to wild situations, consideration should be given to the physical condition of the caged individuals being used. 5. Variation in physical fitness may account for some of the unexplained variation in comparative studies of basal metabolism.