Experimental design schematic, body mass, and muscle morphological characteristics. (a) Four treatment groups (Vehicle control, MET+LEU, MET, and LEU) underwent 14 days of hindlimb unloading followed by 14 days of reambulation/reloading. Black arrows indicate the timepoints at which mice from each group were sacrificed. Age-matched ambulatory baseline (AMB) mice were not given MET+LEU, MET, or LEU and were collected as a baseline reference. Drinking water containing treatments or not (Vehicle control) began on the first day of HU and continued throughout experimentation. (b-d) Body mass in AMB, Vehicle, MET+LEU, MET and LEU. (e-g) Gastrocnemius mass in AMB, Vehicle, MET+LEU, MET and LEU. (h-j) Soleus mass in AMB, Vehicle, MET+LEU, MET and LEU. (k-m) Gastrocnemius cross sectional area (CSA) in AMB, Vehicle, MET+LEU, MET and LEU. (n-p) Soleus CSA in AMB, Vehicle, MET+LEU, MET and LEU.). # p<0.05 vs. AMB, * p<0.05 vs. Vehicle. N=9–14/group for body and tissue mass, N=4–7/group for CSA measures.