By Dr. Sanchari Sinha Dutta, Ph.D. Reviewed by Lauren Hardaker Apr 24 2026 Even when fitness looks normal, hidden changes in oxygen use and microvascular function may already be emerging in adolescents with type 1 diabetes. Study: Cardiovascular and autonomic nervous system response to graded exercise in adolescents with type 1 diabetes . Image credit: Iren_Geo/Shutterstock.com A new study published in  Frontiers in Endocrinology reveals that type 1 diabetes is associated with subtle