Soleus muscle isolation and preparation have previously been described (Moran et al., 2005 (link)). Briefly, the soleus muscle was placed in a 1.2 mL bath filled with oxygenated Krebs-Ringer buffer maintained at 25°C. The proximal muscle tendon was attached by 6–0 suture to a dual-mode muscle lever system (300B-LR; Aurora Scientific Inc.). Measures of peak isometric, concentric, and eccentric forces during tetanic stimulation were obtained as previously described (Greising et al., 2011b (link)).