Interstitial glucose peaked approximately 17% higher during sanctioned competition than during high-intensity training matched on external characteristics in highly trained collegiate male endurance athletes, describing a reproducible pattern of elevated peak glucose in the competitive context.
Interstitial glucose followed a reproducible temporal pattern during competition, rising before the race, peaking during it, and declining afterward.
Mean interstitial glucose during competition was significantly higher than pre-race baseline by approximately 3.12 mM.
Within-subject maximum interstitial glucose was significantly higher during sanctioned competition than during high-intensity training performed at the same prescribed race pace.
The study involved 20 highly trained collegiate male endurance athletes (runners and race walkers) classified at Tier 3 (Highly Trained/National level) who wore CGM across 36 sanctioned races.
The study could not attribute the higher peak glucose in competition to the competitive context itself because internal exercise load was not measured.
This research suggests that blood sugar levels in highly trained competitive endurance runners and race walkers follow a consistent pattern during sanctioned races: levels rise in the hour before competition, peak during the race itself, and then fall after it ends. Using continuous glucose monitors (CGM) worn during 36 real competitions, the researchers found that peak glucose levels averaged around 11–13 mM during races, which is notably elevated compared to typical resting values. This pattern was seen repeatedly across athletes and events, suggesting it is a reliable feature of competitive exercise in this population. One of the most notable findings is that peak glucose during actual competition was about 17% higher than during training sessions that were designed to replicate the same external workload (i.e., the same prescribed pace). This difference raises an interesting question: is the body responding differently to competition itself, or is the athlete simply working harder internally during a real race even when the external pace looks the same? Because the study did not measure internal effort indicators like heart rate or perceived exertion during training, it is not possible to say whether the glucose difference is caused by the psychological or physiological stress of competition or simply by athletes pushing harder internally during races. This research matters because real-world data on blood sugar behavior during actual competitions—rather than lab simulations—are rare for elite athletes. The findings provide a clearer picture of how glucose dynamics unfold in high-stakes endurance events and could inform nutritional strategies for athletes. Future studies that also track internal workload (such as heart rate) during both training and competition would help clarify what is driving the higher glucose peaks seen in races.
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Upload Your LabsKajisa T, Sakai T. (2026). Interstitial glucose during sanctioned competition and during high-intensity training in highly trained collegiate male endurance athletes: A real-world continuous glucose monitoring study.. Physiological reports. https://doi.org/10.14814/phy2.71099