Exercise and the Menstrual Cycle in Type 1 Diabetes

Female participants with type 1 diabetes using oral contraceptives will be asked to wear a continuous glucose monitor for at least three days on two separate occasions (once during the last week of active pills and once during the no pill/placebo pill phase of the menstrual cycle). An exercise session (45 minutes of aerobic exercise at 60% VO2peak on a cycle ergometer) will take place at 5 pm on the second day of glucose monitoring.

Inclusion Criteria: * type 1 diabetes diagnosed for at least 1 year * regular menses * using monophasic oral contraceptives * residing in Edmonton, Alberta and able to visit the lab at the University of Alberta Exclusion Criteria: * HbA1c \> 9.9% * frequent and unpredictable hypoglycemia * change in insulin management strategy within two months of the study * use of an automated insulin delivery system * blood pressure \> 140/95 * history of cardiovascular disease * severe peripheral neuropathy * active proliferative retinopathy * use of medications (other than insulin) that would affect blood glucose levels * any musculoskeletal condition that would contraindicate exercise (e.g. sprain, strain, joint injury, etc.)