Glucose spikes during ultramarathons may not match standard diet or exercise rules

This mini-review examined blood glucose dynamics in ultramarathon runners. The study looked at how sugar levels changed during the race. It found that glucose levels rose in the first phase and then gradually declined in the second phase. In the third phase, variability increased, leading to more transient elevations. By the late stage of the race, blood glucose levels could not be fully explained by conventional factors like carbohydrate intake or exercise intensity. The review noted that direct evidence on this topic remains limited. Safety concerns were not reported in this analysis. Readers should understand that these findings describe patterns rather than proving specific causes. The main reason to be careful is that standard models do not fully predict these late-stage changes. This review suggests that continuous glucose monitors may provide a useful tool for identifying overall trends in glucose dynamics. These tools could support individualized nutritional strategies during ultramarathon running. Patients should discuss fueling plans with their care team before long events.