The primary aim of the study is to compare the efficacy of single-administration low-dose glucagon and split-administration low-dose glucagon to placebo for prevention of exercise-induced hypoglycemia in people with type 1 diabetes using insulin pumps and multiple daily injections (MDI).

The secondary aim is to compare the accuracy of three continuous glucose monitors (CGM) during and after exercise in inpatient and outpatient settings.

A randomized, single-blinded, placebo-controlled three-arm cross-over study will be conducted to assess the study objectives. 22 participants with type 1 diabetes will complete three study visits in random order. At every visit the participants will exercise for 60 min receiving different low doses of glucagon before or before and after exercise compared with placebo.

During the visits and in an outpatient period the participants will have 3 different CGM devices installed and the values will be compared with self-monitored blood glucose values.

Inclusion Criteria:

• Age ≥ 18
• T1D ≥ 2 years
• Use of insulin pump or MDI therapy for ≥ 6 months
• Current use of insulin aspart
• HbA1c ≤ 70mmol/mol (8.5%)
• Body mass index (BMI) ≤ 30 kg/m2
• Performs exercise ≥1 time per week

Exclusion Criteria:

• Use of anti-diabetic medicine (other than insulin), corticosteroids or other drugs affecting glucose metabolism during the study period and within 30 days prior to study start
• Professional athletes or highly active individuals ( ≥ 5 hours of exercise per week)
• Known or suspected allergies to glucagon or related products
• History of hypersensitivity or allergic reaction to glucagon or lactose
• Allergy to the patch of the CGM devices
• Patients with pheochromocytoma, insulinoma or gastroparesis
• Females of childbearing potential who are pregnant, breast-feeding or intend to become pregnant or are not using adequate contraceptive methods (methods are considered adequate for study enrollment for females: an intrauterine device, hormonal contraception (birth control pills, implant, patch, vaginal ring or injection), a single partner who is sterile or infertile, or sexual abstinence. Contraception is required throughout the study duration. Sterilized or postmenopausal women (>12 months since last period) are not required to use contraception)
• Inability to understand the individual information and to give informed consent
• Current participation in another clinical trial that, in the judgment of the investigator, will compromise the results of the study or the safety of the subject
• Concomitant medical or psychological conditions identified through review of medical history, physical examination and clinical laboratory analysis that, according to the investigator's assessment, makes the individual unsuitable for study participation

Single-blinded