Research presented at the European Association for the Study of Diabetes meeting in Milan reveals that with precise insulin, food, and glucose management, individuals with type 1 diabetes can successfully finish endurance races like marathons, challenging longstanding barriers to participation.
New research to be presented at the European Association for the Study of Diabetes meeting in Milan suggests that people with type 1 diabetes can run a marathon safely and post finishing times similar to other runners, provided they plan insulin, food intake and glucose checks carefully. The study, from researchers at Poznan University of Medical Sciences and Raszeja City Hospital in Poland, followed amateur runners in the 2025 Poznań Marathon and found that all of the participants with type 1 diabetes completed the race.
The findings add to a small but growing body of evidence that endurance sport is possible for people with the condition. Previous research published in 2022 on the Paris Marathon reported that real-time continuous glucose monitoring, together with carbohydrate and insulin adjustments, helped prevent hypoglycaemia before, during and after the race. An earlier European Association for the Study of Diabetes and ISPAD position statement also stressed that continuous glucose monitoring and intermittently scanned systems can support safer exercise in type 1 diabetes.
In the Polish study, 10 runners with type 1 diabetes and 10 without diabetes were broadly similar in age and sex. The group with diabetes had a median disease duration of 16.5 years and a median glycated haemoglobin, or HbA1c, of 6.4%, a measure of longer-term glucose control. Their race performance was not meaningfully different from the control group, with median finish times of 228 minutes and 248 minutes respectively.
Glucose management remained the central challenge. Participants with type 1 diabetes were asked to begin the race within a target glucose range and to reduce basal insulin before the start, depending on how they delivered insulin. During the marathon they consumed a median 53.5 grams of carbohydrate an hour. Two low-glucose readings occurred in one runner, who still finished the event. The researchers also found that both intermittently scanned and real-time continuous glucose monitors were less accurate during the race than finger-stick testing, tending to overestimate blood sugar.
The team said their results reinforce the value of preparation, education and individual planning for people with type 1 diabetes who want to attempt demanding endurance events. They advised runners to discuss glucose, carbohydrate and hydration plans with their clinicians beforehand and to confirm sensor readings with a glucometer when symptoms and monitor data do not match. Fear of hypoglycaemia remains a major barrier to exercise, the researchers noted, but well-managed training and racing can allow many people with type 1 diabetes to take part in endurance sport successfully.
Disclaimer: This content is for informational purposes only and is not intended to be a substitute for professional medical judgment, advice, diagnosis, or treatment.
