Insulin resistance biomarkers and related methods of using the biomarkers are provided. The biomarkers may be blood biomarkers and include C-peptide, Insulin-Like Growth Factor-Binding Protein 2 (IGFBP-2), and Leptin. Also provided is a method of reducing the effect of prolonged physical inactivity on insulin resistance in a subject who is experiencing prolonged physical inactivity, or who is expected to experience prolonged physical inactivity in the near future.