Skeletal muscle is known to adapt dynamically to changes in workload by regulatory processes of the phosphatidylinositide 3-kinase (PI3K)/Akt pathway. We performed a global quantitative phosphoproteomics analysis of contracting mouse C2 myotubes treated with insulin growth factor 1 (IGF-1) as control and additionally MK-2206 or LY294002 to inhibit PI3K/Akt signaling, respectively.