Paulsen, KM, Butts, CL, and McDermott, BP. Observation of women soccer players' physiology during a single season. J Strength Cond Res 32(6): 1702-1707, 2018-The purpose of this study was to observe heart rate (HR) responses in match settings over the course of a conference season in National Collegiate Athletic Association Division I women's soccer. Twenty-one female collegiate soccer players were provided a HR monitor and instructed to wear it for the duration of match play. Player positions included 6 defenders (DEF), 6 midfielders (MID), and 9 forwards (FWD). Defenders were further identified as either center defenders (CD) or outside defenders (OD). A 1-way analysis of variance was used to determine if mean HR varied between FWD, MID, and DEF. An independent t-test was used to determine if there was a difference between CD and OD HRs. The FWD, MID, and DEF did have significantly different mean HR (p ≤ 0.05), but post-hoc analysis revealed no significant differences (p ≥ 0.05). However, CD demonstrated significantly lower HRs than OD (p = 0.009). Player position, specifically in the CD and OD role, impact the intensity of exercise in match settings and may be used to specify training and conditioning sessions.