The effects of reducing insulin versus eating carbohydrates on glycaemic control and performance with aerobic exercise in type 1 diabetes

INTERVENTION: 25 Male Participants (in groups of 5 participants at a time) will be performing a walking exercise for 45 mins on a standardized treadmill at a 1% gradient. The brisk walk will be determined by participants trying to maintain the speed of 7.24 kilometers per hour throughout the entire 45 min. Following the aerobic exercise, participants will perform a six‐minute walk test which is a validated measure of predicted VO2 max and will serve as a performance test. This will be followed by a 7 days washout period and then the same group of participants will be repeating the above process for the crossover treatment. Ninety minutes before the exercise all participants on continuous subcutaneous insulin infusion (CSII; known as insulin pump therapy) will start a 50% temporary basal rate reduction as per guidelines. Sixty minutes before the exercise, all participants will eat a carbohydrate predominant mixed meal individualized to contain 0.66 g of carbohydrate/kg of body and 3.375 kcal/kg of body weight, meeting the requirements of both energy expenditure and exercise carbs guidelines Participants in the reduced insulin group will administer 50% of their normal prandial dose of insulin immediately before the meal as a single bolus, with no combo or dual wave boluses allowed. Participants in the exercise carbs group will not administer any prandial insulin or adjust the doses of their basal insulin. The first meal post exercise will be a pre‐prepared lunch of sandwiches and fruit (equivalent to 1 g of carbohydrate/kg of body weight) will be provided. Each patient will be provided with a Freestyle Libre reader and sensor to allow interstitial glucose levels to be measured by Flash Glucose Monitor (FGM) throughout the study period. The sensor will be inserted at least 36‐48 hours before exercise day to ensure accurate calibration. Due to concerns over a several minute lag between changes in interstitial and blood glucose levels, Capillary Bloo CONDITION: Diet and Nutrition ‐ Other diet and nutrition disorders Metabolic and Endocrine ‐ Diabetes Type 1 Diabetes; ; Type 1 Diabetes PRIMARY OUTCOME: The composite primary outcomes of the study are the time of glucose levels in target range (4‐10 mmol/L), the time of glucose levels in hypoglycaemia (<4.0 mmol/L), the time of glucose levels in hyperglycaemia ( > 10.0 mmol/L). Both the outcomes will be assessed by measuring the capillary blood glucose using a glucometer and further assessed by laboratory assay of blood sample.; [Monitored from the start of the exercise day (baseline), during (every 15 minutes of the exercise) and in the four hours following 45 minutes of aerobic exercise.] SECONDARY OUTCOME: The composite secondary outcome is the effects on capillary Ketone and lactate levels. ; Ketone and blood lactate as assessed by laboratory assay of blood sample. ; [Monitored from the start of the exercise day (baseline), during (every 15 minutes of the exercise) and in the four hours following 45 minutes of aerobic exercise.] The effects on predicted VO2 max as a marker of performance as assessed using the 6 minute walk test and using a heart rate monitor[Monitored from the start of the exercise day (baseline), during and in the four hours following 45 minutes of aerobic exercise.] INCLUSION CRITERIA: Patients diagnosed with type 1 diabetes (T1D). T1D Men (but not on testosterone replacement therapy) Patients competent at self‐management of all diabetes tasks T1D patients who have an HbA1c of 45 ‐ 90 mmol/mol (within the last 3 months) T1D patients who are able to walk unaided for 45 mins at a fast pace (7 km/h) T1D patients on treatment with a traditional insulin pump therapy