Fasted Exercise in People With Type 1 Diabetes

This study aims to compare the effect of a bout of high-intensity interval training (HIT) with a bout of moderate-intensity continuous training (MICT) on glucose concentrations over the subsequent 24h period. Fourteen people with type 1 diabetes (duration of type 1 diabetes 8.2±1.4 years), all on basal-bolus regimen, completed a randomised, counterbalanced, crossover study. Continuous glucose monitoring was used to assess glycaemic control following a single bout of HIT (6 x 1min intervals) and 30 mins of moderate-intensity continuous training (MICT) on separate days, compared to a non-exercise control day (CON). Exercise was undertaken following an overnight fast with omission of short-acting insulin. Capillary blood glucose samples were recorded pre and post-exercise to assess the acute changes in glycaemia during HIT and MICT.

Inclusion criteria

• duration of type 1 diabetes >6 months
• basal bolus regimen
• no significant history of hyper- or hypoglycaemia (determined from medical history

Exclusion criteria

• duration of type 1 diabetes <6 months,
• insulin pump therapy
• significant history of hyper- or hypoglycaemia (determined from medical history)
• obesity (BMI >30 kg∙m-2)
• pregnancy or planning pregnancy, uncontrolled hypertension (>180/100 mmHg)
• angina
• autonomic neuropathy
• taking any medication that affects heart rate
• major surgery planned within 6 weeks of the study
• severe nonproliferative and
• unstable proliferative retinopathy