Current medical guidelines for returning to physical activity postpartum provide little to no information on a progression for returning to running. Little is known about female runners returning to running following pregnancy, particularly in terms of running biomechanics, running habits, and overall well-being. A critical gap in developing “return to play” guidelines for postpartum runners is a lack of information about the extent to which differences in running-related characteristics that develop during pregnancy fail to restore to pre-pregnancy levels postpartum. This project seeks to track changes in gait biomechanics, foot and body morphology, general health, and physical activity habits of habitual runners through and after pregnancy.