Figure 1.

Physical activity of SAAR mice is influenced by age. (a) Young male mice were defined as 8 weeks old and fed either control (CF, 0.86% met w/w, white bars or circles) or SAAR (0.12 met w/w, black bars or circles) for 52 weeks. (a) Aged male mice were defined as 2 years old and fed either diet for 15 weeks. White dots within bar graphs indicate values from each animal. Muscle mass (b) was obtained from the quadriceps femoris of each mouse. Physical activity was assessed by wire hang shown as holding impulse (c), and accelerated rotarod (d) were performed 2 weeks prior to sacrifice. Distance run (e and f) and speed (g and h) from 24-h in-cage voluntary running wheel measurements collected every 2 weeks after 6 months on the diets. Statistical analysis was conducted using 2-way ANOVA with Sidak post hoc test, as described in methods (n = 5–8 per group, ^*P < 0.05, ^**P < 0.01, ^****P < 0.0001).