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.
To describe the training effects in mice given long-term aerobic voluntary exercise.
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, V̇O2peak, speed at V̇O2peak, and citrate synthase (CS), succinate dehydrogenase (SDH), and phosphofructokinase (PFK) activity in the soleus, plantaris, and red and white gastrocnemius were assessed.
Final body weight and speed at V̇O2peak did not differ by training condition. WR mice had significantly longer RTE times (P < 0.001) and higher V̇O2peak (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).
Voluntary running wheel activity for 16 wk in female C57BL/6 mice resulted in longer run times to exhaustion, higher V̇O2peak, 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.
1Department of Health Studies and Gerontology and 2Department of Kinesiology, Faculty of Applied Health Studies, University of Waterloo, Waterloo, Ontario, CANADA
Address for correspondence: Laurie Hoffman-Goetz, PhD, MPH, Department of Health Studies and Gerontology, Faculty of Applied Health Studies and Gerontology, University of Waterloo, 200 University Avenue West, Waterloo, Ontario, N2L 3G1 Canada; E-mail: email@example.com.
Submitted for publication April 2005.
Accepted for publication August 2005.