Minimum Overnight Interstitial Glucose Concentration in Professional Cyclists During Two Consecutive Annual Training Camps: The Limited Impact of Daily Exercise Energy Expenditure

This observational study investigated the use of continuous glucose monitoring (CGM) in a team of professional cyclists without diabetes during two consecutive annual training camps. The goal of the study was twofold: to present the aggregated CGM metrics such as day/overnight CGM average (DAYAVG/OVNAVG) for this group of professional cyclists and to study the association between exercise energy expenditure (megajoules per day), carbohydrate intake (grams), and minimum overnight CGM values (millimoles per liter). Linear mixed models were employed in the analysis. Data were available for 26 cyclists (22 participated in both training camps). CGM levels reported (DAYAVG = 6.37 ± 0.54 mmol/L and OVNAVG = 5.30 ± 0.52 mmol/L), are not typically seen in healthy individuals not engaged in intensive exercise routines. Results showed that minimum overnight CGM values significantly fluctuated throughout the training camp, but a statistically significant association between exercise energy expenditure (p = .0839) or carbohydrate intake (p = .059) and minimum overnight CGM values could not be detected. This research contributes to the literature on CGM use in professional athletes and underscores the need for further studies to fully understand the benefits and limitations of CGM to guide sports performance.