Building and Sustaining Exercise Habits for Adults With Type 1 Diabetes

Inclusion criteria: * 30-65 years old inclusive * Diagnosis with type 1 diabetes (T1D) or other insulin deficiency diabetes (latent autoimmune disease of adulthood, diabetes secondary to pancreatitis) * Less than 1.0 exercise sessions per week * Smartphone ownership * English literacy * Under regular care by a healthcare provider (1+ appointments per year) * Home Broadband wireless Internet or cell phone network * Using continuous glucose monitor (CGM) and sharing data with medical record for at least 6 weeks * Using insulin pump or pen and sharing data with medical record for at least 6 weeks Exclusion criteria: * Diabetic ketoacidosis not clearly related to pump site failure in past 6 months * \>1 episode of severe hypoglycemia (altered mental and/or physical status requiring assistance from another person for recovery) in past 6 months * A1c ≥10.0% * Resting blood pressure \>160mmHg systolic or \>100 mmHg diastolic. * Myocardial infarction or angina in past 12 months * Uncontrolled arrhythmia (e.g., atrial fibrillation with rapid ventricular response, new onset atrial fibrillation, ventricular tachycardia, escape rhythms) * Congestive heart failure (stage 3 or 4) * Exercise-induced asthma (not controlled on inhalers) * Chronic obstructive pulmonary disease (requiring home oxygen) * Renal failure * Pregnancy * Cognitive impairment * Severe retinopathy or neuropathy. * Other chronic disease or physical disability that would influence exercise intervention (e.g., recent spinal surgery)