The IPHY Department's Locomotion Lab is in need of subjects for a running study on the efficiency and biomechanics of running shoes. Subject criteria: -Males between 18-45 years old; -Have run a 10 km in 31 minutes or less; -Have no current musculoskeletal injuries; -Wear a size 10 running shoe. It is a 4-day study where subjects will run at 14,16 and 18 km/h for various trials. All 5' in length. Subjects will be compensated $200 for their time (or $50 a session). Contact curunningstudy@gmail.com if interested.