Figure 4. Fiber type composition of muscles from mice flown on board ISS and ground-based controls.

Fiber type compositions of EDL and soleus muscles from mice housed in normal laboratory cage (open bars; n = 3, data are expressed as means ± SEM), ground control housed in MDS payload (light blue bars, n = 1), and spaceflight mouse housed in MDS payload (blue bars; n = 1). The prolonged exposure to the microgravity environment caused a slow-to-fast rearrangement of fiber type composition in soleus muscle, but not in EDL.