In Amateur Athletes With Type 1 Diabetes, a 9-Day Period of Cycling at Moderate-to-Vigorous Intensity Unexpectedly Increased the Time Spent in Hyperglycemia, Which Was Associated With Impairment in Heart Rate Variability.

In sports enthusiasts with type 1 diabetes, multiday prolonged exercise at moderate-to-vigorous intensity worsened hyperglycemia, with hyperglycemia negatively associated with parasympathetic cardiac tone. Considering the putative deleterious consequences on cardiac risks, future work should focus on understanding and managing exercise-induced hyperglycemia.