Training effects in mice after long-term voluntary exercise.
BACKGROUND
Mice are an important animal model in exercise studies on the immune system, cancer, and aging. There is limited research about the training effects of long-term voluntary exercise in this species.


OBJECTIVE
To describe the training effects in mice given long-term aerobic voluntary exercise.


METHODS
Female C57BL/6 mice were randomly assigned to 1) individual cages with in-cage running wheels with 24-h access (WR; N = 31), or 2) individual cages without running wheels for 16 wk (NR; N = 20). Run-to-exhaustion (RTE) times, VO2peak, speed at VO2peak, and citrate synthase (CS), succinate dehydrogenase (SDH), and phosphofructokinase (PFK) activity in the soleus, plantaris, and red and white gastrocnemius were assessed.


RESULTS
Final body weight and speed at VO2peak did not differ by training condition. WR mice had significantly longer RTE times (P < 0.001) and higher VO2peak (P < 0.05) compared with NR mice. Higher CS and SDH activities were found in WR compared with NR mice for soleus (P < 0.01), red gastrocnemius (P < 0.01), and plantaris (P < 0.01) muscles. PFK activity was higher in WR mice in white gastrocnemius compared with NR mice (P < 0.01).


CONCLUSIONS
Voluntary running wheel activity for 16 wk in female C57BL/6 mice resulted in longer run times to exhaustion, higher VO2peak, and higher SDH and CS activities in oxidative muscles. These findings suggest that wheel running in female C57BL/6 mice: 1) produces a measurable aerobic training effect and 2) is an effective exercise modality for long-term training studies.
Department of Health Studies and Gerontology, Faculty of Applied Health Studies, University of Waterloo, Waterloo, Ontario, Canada.
Sara R
SR
Davidson
Margaret
M
Burnett
Laurie
L
Hoffman-Goetz
D000704:Analysis of Variance; D000818:Animals; D001835:Body Weight; D002950:Citrate (si)-Synthase / Q000378:metabolism; D005260:Female; D051379:Mice; D008810:Mice, Inbred C57BL; D018482:Muscle, Skeletal / Q000201:enzymology*; D010101:Oxygen Consumption / Q000502:physiology; D010732:Phosphofructokinase-1 / Q000378:metabolism; D010805:Physical Conditioning, Animal; D018709:Statistics, Nonparametric; D013385:Succinate Dehydrogenase / Q000378:metabolism
D013385:Succinate Dehydrogenase; D002950:Citrate (si)-Synthase; D010732:Phosphofructokinase-1