(56) Ambient Temperature Related Decrements in Performance Characteristics of NCAA D-I Female Soccer Players

Soccer players are exposed to various environments during outdoor play, thereby increasing their risk of heat-related performance decrements.

Purpose: To examine the effects of heat stress on characteristics of performance during collegiate soccer matches.

Methods: Global positioning system (GPS) data from female soccer players within a Midwestern NCAA Division-I soccer program were collected during the 2023 regular season. All players were instructed to wear the GPS tracking system with the capability of heart rate (HR) monitoring throughout all the 18 games. All data were collected continuously, regardless of if players were substituted in or out of play, therefore all data were made relative to minutes played. Matches were further categorized into thirds based on temperature. Matches with temperatures exceeding 75°F were considered high heat, while matches with temperatures between 60 – 74°F were moderate heat, and temperatures less than 60°F were categorized as low heat. GPS data were then divided into 1^st and 2^nd halves for players who averaged more than 20 minutes of playing time over the course of the season. The performance characteristics measured were number of sprints, percent of time spent running at low speed (LSR) zones and high speed (HSR) zones (≥15 km/hr), total time spent in low heart rate (LHR) zones and high HR (HHR) zones (≥80% of HR reserve), total distance covered (TDC), and training load (TL). Repeated measures analysis of variance was used to analyze differences between the half and temperature category (High vs low heat) with an alpha (α) set at ≤0.05. Post-hoc paired sample t-test were performed to further elucidate interactions.

Results: A significant interaction was observed for the number of sprints (F=5.449, p=0.038) and duration of time spent within the HHR zone (F= 6.67, p=0.024). Post hoc comparisons indicated that the number of sprints completed in the 2^nd half of the high heat matches were reduced when compared to the first half of the high heat matches (p=0.018), and the 2^nd half of low heat matches (p=0.019). Additionally, data indicated that the time spent running in HHR zones during the 2^nd half of the low temperature matches was lower than that of the 1^st half (p=0.011). Main effects of temperature indicate greater time HSR zones (F= 5.73, p=0.034) and in TL (F=6.40, p=0.026) in low temperatures compared to high temperatures. Main effects for half indicate more time spent in the L-HR zones (F= 34.3, p ≤ 0.001) during the 2^nd half. Data are presented in Table 1. Conclusion: The number of sprints performed was lower in high temperature matches while the duration of time spent in HHR zones was higher in high temperature matches. Practical Application: Coaches may utilize this information to optimize training loads leading to competition with higher temperatures.


Acknowledgements: Acknowledgments: We extend our gratitude to all players and coaches from the soccer program for their support with this project.