Figure 2.

Mean distance run per 24 h (±SEM) calculated weekly over the 12 weeks of the study in rats (n = 8) given voluntary access to running wheels. As is typically observed in Sprague–Dawley rats, the daily average distance run increased initially until the fourth/fifth week of running, and gradually decreased thereafter. Repeated measures ANOVA on mean running distances was significant (p = 0.002), as was the quadratic component (p = 0.048).