The purpose of this project is to investigate whether the glucose response in type 1 diabetes patients measured using Continuous Glucose Monitoring measurement is reproducible in repeated standardized test sessions that include physical activity.

Inclusion Criteria:

• Type 1 diabetes with a diabetes duration of at least 2 years
• age 18-60 years (inclusive)
• given informed consent
• exercises (at least 30 minutes intentional exercise where participants feel exhausted) one or more times a week
• participants agree to use CGM correctly

Exclusion Criteria:

• pregnancy
• exercising at a high level (five or more times a week with high intensity)
• treatment with prednisolone or less than a month ago contestant has been treated with prednisolone
• treatment with beta blockers
• Abuse of alcohol / drugs

20 patients with type 1 diabetes (treated with or without insulin pump) will participate in three identical test sessions on an exercise bike. During the three test sessions, patients will be monitored by heartrate, blood glucose (obtained by lancet) and CGM. The participants will also be using a diary for registration of diet as well as exercise during the study.