Inclusion Criteria:  Age of 14-19 years Diagnosis of type 1 diabetes or other absolute insulin deficiency diabetes for ≥6 months Inadequate moderate-to-vigorous physical activity levels (defined as ≤3 days per week achieving ≥60min daily, which is ≤50% of the recommended 7 days per week) English literacy Own a continuous glucose monitor (Dexcom G4, G5, G6 [San Diego, CA], Abbott Freestyle Libre 2, 14-day [Chicago, IL], Medtronic Guardian 3, Enlite [Dublin, Ireland]) with enough supplies for 6 weeks (when available, we will provide these to those who do not own them, in which case they will be considered to meet this criteria). Access to television or computer with HDMI or USB port. Under regular care by a healthcare provider (defined as attending at least one appointment in the past year, plus access to verified 24hr phone number to reach the provider's team for insulin dose adjustments if assistance is needed)  Exclusion Criteria:  • A condition or disability besides type 1 diabetes that would preclude participation in group moderate-to-vigorous physical activity (e.g., cerebral palsy, current pregnancy)