Proteomic characterization of skeletal muscle biopsies collected from the vastus lateralis of 44 male and female human subjects. Research subjects were divided in three different groups based on their individual exercise backgrounds and physical performance testing: 1) endurance trained (males; ME, n = 9 and females; FE, n = 9, with at least 15 years’ of regular training experience), 2) strength-trained males (MS, n = 9, with at least 15 years’ of regular training experience), and 3) age-matched healthy untrained controls (males, MC, n = 9 and females FC, n = 8, with a self-reported history of <2 exercise bouts per week over the past 15 years).