Glucose‐lowering effects of physical activity in type 1 diabetes: A causal modelling and matched‐pair analysis approach

Journal article

Aims: To evaluate the acute glucose‐lowering effect of bouts of physical activity (PA) for hyperglycaemia in individuals with type 1 diabetes, using a within‐subject matched‐pairs causal design to approximate the control condition of no activity. Methods: Data comprised 1546 PA bouts of 10–30 min from 482 participants in the T1DEXI and T1DEXIP cohorts where glucose was >10 mmol/L. Each PA bout was matched [starting glucose, glucose rate of change, insulin on board (IOB) and glucose variability (CV)] to a matched non‐PA period within the same individual using a weighted k‐nearest neighbours algorithm (SMD <0.01). Primary outcome: Change in glucose from PA onset to 20 min post‐activity. Secondary outcomes: Predictors of glucose response and rate of hypoglycaemia incidence. Results: PA [median 23 min: IQR (20, 30)] led to a mean glucose change of −2.2 mmol/L (p < 0.001), compared with 0.3 mmol/L (p < 0.001) during matched non‐PA periods (mean difference: −1.9 mmol/L (p < 0.0001)). No significant differences by age, activity type or intensity were observed. The strongest predictors of PA‐induced glucose change were (in order) glucose rate of change, starting glucose, CV, duration and IOB. A heatmap using starting glucose and glucose rate of change was developed to guide real‐time decision‐making. PA‐induced hypoglycaemia risk was very low (<2%). Conclusion/Interpretation: Using PA to lower high glucose levels is an effective and safe strategy, and when guided by CGM, it can become a personalised tool for type 1 diabetes education.

Authors: Pemberton, JS; Russon, CL; Pulsford, RM; Metcalf, BS; Cockcroft, E

• Publication status: Published
• Peer review status: Peer reviewed
• Publisher: Wiley
• Journal: Diabetic Medicine
• Article number: e70146
• Publication date: 2025-10-08
• Acceptance date: 2025-09-19
• DOI: 10.1111/dme.70146
• EISSN: 1464-5491
• ISSN: 0742-3071
• Language: English
• Keywords: endocrine; exercise; Diabetes