The present invention relates to compositions and methods for treating and preventing skeletal muscle deficiencies. In particular, the present invention provides compositions comprising poloxamers (e.g., poloxamer 188 - P188) and methods of using the same for treating and preventing skeletal muscle deficiencies and injuries (e.g., dystrophin-deficient skeletal muscle; skeletal muscle having a contraction force deficit; skeletal muscle having a Ca 2+ imbalance; skeletal muscle having microtears).