Full Breakdown
Marathon Completion Safe for Runners with Type 1 Diabetes, New Study Shows
By Drooid · · How we work
Core Findings
A small controlled trial demonstrated that ten adults with type 1 diabetes finished a 26.2-mile marathon in roughly the same time as ten non-diabetic peers. The diabetic runners averaged about 228 minutes, while the control group averaged 248 minutes. Only one diabetic participant experienced two episodes of hypoglycemia during the race and still completed the distance.
Background & Context
Fear of hypoglycemia deters up to 45 % of people with type 1 diabetes from engaging in regular exercise, despite the known cardiovascular and metabolic benefits. Managing glucose during prolonged, high-intensity activity is challenging because insulin needs fluctuate rapidly and individual responses vary.
Study Design & Data
- Participants: 20 adults (10 with type 1 diabetes, 10 without). Average ages were 35 years for the diabetic group and nearly 40 years for the control group; each cohort comprised eight men and two women.
- Pre-race glucose target: 140–200 mg/dL for diabetic runners.
- Insulin adjustments:
- 25 % reduction for those using multiple daily injections,
- 50 % reduction for users of non-hybrid insulin pumps,
- Hybrid closed-loop pump users set a target of 150 mg/dL.
- Monitoring: Blood glucose was measured at the start, three checkpoints along the course, and at the finish; carbohydrates or insulin were administered as needed.
- Outcomes: One participant began the race with a glucose level below 140 mg/dL and consumed slightly less carbohydrate (just under 50 g per hour) than the other diabetic runners (nearly 54 g per hour).
Official Statements & Responses
The investigators added that athletes should develop individualized glucose, carbohydrate, and hydration plans with their physicians before attempting a marathon.
Limitations & Gaps
The investigators noted that the findings were presented at a professional meeting and have not yet undergone peer-review. Consequently, the results should be considered preliminary until published in a scientific journal.
Why It Matters
Demonstrating comparable marathon times and low hypoglycemia incidence suggests that, with tailored insulin strategies, the barrier of fear may be reduced for people with type 1 diabetes who wish to pursue endurance sports. This could broaden participation in high-intensity exercise, offering additional health benefits to a population that often avoids such activities.
What’s Next
The study results will be discussed at the upcoming European Association for the Study of Diabetes (EASD) meeting in Milan later this month. The American Diabetes Association also provides guidance on exercising with type 1 diabetes for clinicians and patients seeking further information.