Meeting Abstract

108.2  Tuesday, Jan. 7 08:30  Effects of voluntary exercise on spontaneous physical activity and food consumption in mice: results from an artificial selection experiment COPES, L.E.; SCHUTZ, H.; DLUGOSZ, E.M.; ACOSTA, W.; CHAPPELL, M.A.; GARLAND, T.*; Quinnipiac Univ.; Pacific Lutheran Univ.; Univ. of California, Riverside; Univ. of California, Riverside; Univ. of California, Riverside; Univ. of California, Riverside tgarland@ucr.edu

We evaluated the effect of voluntary exercise on spontaneous physical activity (SPA) and food consumption in mice from 4 replicate lines selectively bred for 57 generations for high voluntary wheel running (HR) and from 4 non-selected control (C) lines. Beginning at ~24 days of age, mice were housed in standard cages or in cages with attached wheels. Wheel activity and SPA were monitored in 1-min intervals. Data from week 8 were analyzed because mice were adult and had plateaued in body mass, weekly wheel running distance, SPA, and food consumption. SPA of both HR and C mice decreased with wheel access, due to reductions in both duration (min/day with any cage activity) and average intensity of SPA. However, total activity (SPA + wheel running) duration (min/day) was ~1/3 greater when mice were housed with wheels, and food consumption was significantly increased. Overall, food consumption in both HR and C mice was more strongly affected by wheel running than by SPA. Duration of wheel running had a stronger effect than average speed, but for SPA the relative effects of intensity versus duration varied depending on which subset of mice was analyzed. As both HR and C mice housed with wheels had increased food consumption, the energetic cost of wheel running was not fully compensated by concomitant reductions in SPA. Both duration and intensity of both wheel running and SPA were significant predictors of food consumption. This sort of detailed analysis of the effects of different aspects of physical activity on food consumption has not previously been reported for a non-human animal, and it sets the stage for longitudinal examination of energy balance and its components in rodent models.