Fasted Exercise Training in Type 1 Diabetes (FED-T1D)

Inclusion Criteria:

1. Clinical diagnosis of type 1 diabetes for 5 or more years.

2. Treatment using an insulin pump with no change in treatment modality for > 2continuous months and willing to share CGM data with the research team. Insulindelivery can be managed using either manual open-loop system (non-AID) or a hybridclosed loop (AID) systems.

3. Using rapid (e.g., Aspart, Lispro or Glulisine) or ultra-rapid (e.g., FiAsp) actinginsulin analogs.

4. HbA1c 7.0-9.9%.

5. Have BMI of 25 kg/m2 or above

6. Have waist circumference associated with central obesity/metabolic syndrome as perDiabetes Canada definition

• 94cm for males of European, Sub-Saharan African, Eastern Mediterranean andMiddle Eastern descent

• 90cm for males of South Asian, Chinese, Japanese, South and Central Americandescent

• 80cm for females

7. No history of stroke, myocardial infarction, or coronary artery disease

8. Not wearing implantable device such as a pacemaker, neurostimulators, aneurysmclips, metal fragments, epicardial electrodes, cochlear implants, magnetic ocularimplants, penile implants, magnetic tissue expander, some types of breast implants,magnetic orthopedic implants, magnetic dental implants, hearing Aids, intravascularimplants, for example VCI filters, coils, stents, cardiac septum implants,ventricular bypass devices.

9. Use a CGM in routine diabetes management.

Exclusion Criteria:

1. Major complication within the previous 3 months (e.g., severe hypoglycemia requiringassistance, diabetic ketoacidosis, or cardiovascular event).

2. Restriction in aerobic or resistance exercise due to significant diabetescomplications (e.g., severe peripheral neuropathy, active proliferative retinopathy,etc.) or other type of limitations (e.g., orthopedic, severe arthritis, etc.).

3. Uncontrolled hypertension (e.g., blood pressure >160 mmHg systolic or >100 mmHgdiastolic).

4. Implanted device, material, or having a condition contraindicated to MRI.

5. Ongoing pregnancy or breastfeeding.

6. Inability to give consent.

7. Use of an injection-based insulin therapy (ex. multiple daily injections or combinedpump and injection-based delivery).