Exercise in type 1 diabetes: real-world data on glucose levels and hypoglycaemia risk from over 420,000 exercise sessions

AIMS/HYPOTHESIS: This large observational cohort real-world study explored the effects of three forms of exercise (walking [WALK], aerobic excluding walking [AER] and anaerobic [ANAER]) on glucose levels and hypoglycaemia risk in type 1 diabetes. METHODS: Data were collected from 3248 users of mySugr Logbook and Apple Health (mean ± SD age 41.23±12.25 years; glucose management index of 7.05±1.09%; 41.5% were female) over a total of 428,058 exercise sessions. Acute and 24 h glycaemic effects were examined across exercise types. Post-exercise glycaemia data over 24 h were compared with sedentary glycaemic data. Time of exercise was used to assess the probability of nocturnal hypoglycaemia. RESULTS: Independent of type, exercise decreased glucose by -1.06±0.89 mmol/l. For the individual types of exercise, WALK decreased levels by -1.24±0.81 mmol/l, AER by -1.43±1.02 mmol/l and ANAER by -0.52±0.81 mmol/l (all p