High-Risk Environmental Conditions Attenuates Performance Efficiency Index in NCAA DI Female Soccer Players

The purpose of this study was to evaluate the effects of environmental conditions on running performance and performance efficiency index (Effindex). Performance data recorded using Polar Team Pro sensors from eight collegiate female soccer players in nine matches were analyzed during the 2019 competitive season. Effindex and running performance, including total distance covered (TD_REL) and distance covered in five speed thresholds relative to minutes played, were examined for indications of fatigue with respect to environmental conditions, including ambient temperature and relative humidity. Matches were separated into three groups based on environmental conditions: Low-Risk (n = 2 matches), Moderate-Risk (n = 3 matches), or High-Risk (n = 4 matches). Speed thresholds were grouped as follows: walking (WALK_REL), jogging (JOG_REL), low-speed running (LSR_REL), high-speed running (HSR_REL), and sprinting (SPRINT_REL). A significant effect was observed for TD_REL in all environmental conditions (η² = 0.614). TD_REL was significantly lower in the High-Risk (p = 0.002; 95.32 ± 12.04 m/min) and Moderate-Risk conditions (p = 0.004; 94.85 ± 9.94 m/min) when compared to Low-Risk (105.61 ± 9.95 m/min). WALK_REL (p = 0.005), JOG_REL (p = 0.005) LSR_REL (p = 0.001), HSR_REL (p = 0.035), SPRINT_REL (p = 0.017), and Effindex (p = 0.0004) were significantly greater in Low-Risk conditions when compared to Moderate-Risk conditions. WALK_REL (p = 0.005), HSR_REL (p = 0.029), SPRINT_REL (p = 0.005), and Effindex (p = 0.0004) were significantly greater in Low-Risk conditions when compared to High-Risk conditions. High-Risk environmental conditions may result in adverse performance in female collegiate soccer players.