Additional file 1: Figure S1. of Voluntary resistance wheel exercise from mid-life prevents sarcopenia and increases markers of mitochondrial function and autophagy in muscles of old male and female C57BL/6J mice

Murf1 (A) and Atrogin-1 (B) mRNA in quadriceps muscles of 15-month SED, 23-month SED, and 23-month RWE mice, of both sexes. Gene expression in the quadriceps muscles was normalized to the geometric mean of Hprt and Ppia expression values. Data were analyzed by ANOVA, using age and sex, and sex and activity as variables. Data are mean ± SEM. Asterisk (*) denotes significance at *P < 0.05; **P < 0.01; ***P < 0.001. For each age group, N = 5–9 mice/group. Y-axes represent arbitrary units