Monitoring core temperature, match running characteristics and performance indicators during professional football in men and women.

OBJECTIVES: To explore associations between environmental conditions, core temperature and running characteristics during 2024-2025 A-League Men's (ALM) and Women's (ALW) matches. DESIGN: Longitudinal cohort study. METHODS: Gastrointestinal temperature (Tgi) and match running characteristics were recorded on 100 occasions in seven ALM (n = 35) and 20 ALW (n = 65) players across 11 and 13 matches, respectively. Environmental conditions, including wet-bulb globe temperature (WBGT), were measured in all matches. RESULTS: Average match conditions were 27.1 °C, 57% relative humidity and 22.7 °C WBGT for ALM, and 29.4 °C, 48% relative humidity and 24.7 °C WBGT for ALW (P ≥ 0.18). Mean peak Tgi in ALM (39.4 °C [39.2, 39.7]) was significantly higher than in ALW (39.1 °C [38.9, 39.2]; P = 0.03). Tgi exceeded 40 °C on seven occasions in six players (3 ALM, 3 ALW) with highest values of 40.8 °C (ALM) and 40.1 °C (ALW). Mean total running distance for players who completed ≥90 min of match play was 10,879 m [10,124, 11,634] for ALM and 10,500 m [10,047, 10,954] for ALW (P = 0.38). Distance covered at high intensity was 679 m [480, 879] for ALM and 485 m [366, 604] for ALW (P = 0.10). A 1 °C rise in WBGT was associated with an increase in peak Tgi in ALM (0.05 °C [0.02, 0.09], P < 0.01) but not ALW (0.0 °C [-0.03, 0.05], P = 0.56) and had no association with running characteristics. CONCLUSIONS: Professional footballers experience considerable thermal strain during competitive match play across different environmental conditions. Given the absence of any meaningful association of WBGT with peak Tgi and running characteristics, alternative methods to quantify heat illness risk in professional football should be explored.