Glucose Variability in Elite Female Soccer Players: A Pilot Study Using Interstitial Monitoring on Match Day

Observing fluctuations in blood sugar during competitive events yields significant data regarding the metabolic demands placed upon athletes. This investigation sought to delineate the glycemic characteristics of top-level female soccer players throughout official matches. A total of ten elite women’s soccer players (age: 27.2 ± 3.8 years; BMI: 21.7 ± 1.5 kg/m2) from the same team had their interstitial glucose (iG) levels recorded via continuous glucose monitoring (CGM) throughout two distinct match cycles. External physical workloads were captured using global positioning systems. The athletes were categorized by their playing role, as starters or bench players, and the observation window was partitioned into four segments: night-time, pre-match, match, and post-match. Data indicated a between-subject coefficient of variation (CV) of 13% and a within-subject CV of 17%. Starting players showed elevated variability (16% between; 20% within) relative to bench players (9% and 13%). While temporal factors remained stable, playing status influenced iG significantly (F = 5.44, p = 0.006, ηp2 = 0.44). Specifically, starters experienced higher iG during competition versus night (+26.5 mg/dL, p = 0.001), pre-match (+22.2 mg/dL, p = 0.002), and post-match (+25.9 mg/dL, p = 0.004). These findings suggest that CGM may assist staff in developing tailored nutritional interventions, given the wide range of individual responses found in this unexplored field.