People with Type 1 Diabetes (T1D) often receive limited or generic advice on managing glucose levels during and after exercise. This project introduces a novel approach—netIOB (net Insulin On Board)—as a more accurate and actionable metric than conventional, bolus-only IOB. By combining netIOB with predictive forecasts, we aim to build research tools that help people understand insulin dynamics around exercise. These monitoring outputs are not dosing or treatment recommendations.
Unlike traditional “absolute IOB,” which focuses on bolus insulin only, netIOB reflects all increases and decreases in insulin delivery, including basal rate adjustments and pump suspensions. This offers a more realistic picture of active insulin levels, especially around exercise. Our initial analyses show that netIOB better captures the insulin dynamics responsible for post-exercise glucose fluctuations and can potentially reduce the risk of hypoglycaemia and rebound hyperglycemia.
We're developing tools to help people with T1D, caregivers, and clinicians understand netIOB and apply it in everyday decisions around exercise. These resources will be based on real-life scenarios and support adoption across diverse diabetes technologies. We also recognise that netIOB may have wider applications outside of exercise, including meal-time decision-making, pump disconnection scenarios, and menstrual cycle-related insulin sensitivity changes.
We’re laying the foundation for a future pilot study to test the impact of netIOB & customized predictions on glucose outcomes across a range of exercise scenarios. Our vision is to bring netIOB into mainstream insulin delivery systems, improving glycaemic management tools for all individuals living with T1D.
Rayhan Lal (Stanford)
Dessi Zaharieva (Stanford)
Ramesh Johari (Stanford)
Emily Fox (Stanford)
Dana Lewis (OpenAPS)
Ricardo Carbajo (CeADAR)
Rachel Guo (Stanford)
Ana Cortes (Stanford)
Ilenia Balisteri (Stanford)
Ryan Kingman (Stanford)
Bailey Suh (Stanford)
Lauren Figg (Stanford)
Matthew Levine (Broad Inst.)
Michael Riddell (York Uni.)
Abiodun Solanke (CeADAR)
Saad Shahid (CeADAR)
“By validating netIOB as a clinically relevant metric, we aim to improve the safety and confidence of people with T1D to engage in physical activity — ultimately enhancing quality of life.”
New research from CeADAR investigates glycemic variability (GV) before and after hypoglycemia in people with T1D, comparing users of automated insulin delivery (AID) systems and those without.
Helmsley Charitable Trust commits $12M to help people with T1D safely include exercise in their daily routines.
T1D Exercise Initiative funds 7 new projects to improve devices, algorithms, education, and interventions supporting exercise in T1D.