Investigating the metabolic effects of whey protein ingestion prior to exercise in adults with type 1 diabetes.

The participants will undertake a range of exercise sessions with varying pre-exercise conditions and different exercise durations. All exercise sessions will be moderate intensity (50% of their VO2 max) aerobic exercise sessions conducted on a cycle ergometer (exercise bike). At screening individuals will participate in a VO2 max session to discover the appropriate testing value. For each of the conditions participants will either ingest a whey protein isolate drink (True Protein, Whey Protein Isolate 90) mixed with 200ml of water, measured to ensure a protein content 0.5g/kg of body weight, or a control drink containing just 200ml of water in random order. The whey protein or control drink will be consumed within a 5 minute timeframe and once completed the participant will commence exercise activity 30 minutes later. This will be done under supervision of one of the study investigators, whom will also supervise the exercise sessions. There will be four exercise sessions, each to be completed twice by each participant, (one control and one whey protein). Session A will require a pre-exercise meal and insulin bolus to be administered 4 hours prior to exercise with a temporary target set on the automated insulin delivery (AID) device 2 hours pre-exercise. The exercise duration of this session will be 60 minutes. This session will be mandatory for all participants whom consent to be apart of the study to participate in. Sessions B, C and D will all be additional optional studies for participants to complete, however they must complete both protein and control sessions for each different exercise condition. Session B will require a pre-exercise meal and insulin bolus to be administered 2 hours prior to exercise with a temporary target set on the AID device 2 hours pre-exercise. The exercise duration of this session will be 60 minutes. Session C will require a pre-exercise meal and insulin bolus to be administered 4 hours prior to exercise with a temporary target set on the AID device 2 hours pre-exercise. The exercise duration of this session will be 90 minutes. Session D will be a rest session in which blood sample analysis will be completed. Individuals will consume a pre-exercise meal and insulin bolus will be administered 2 hours prior to the beginning of the rest session with a temporary target set on the AID device 2 hours before. Blood sampling will be done every 10 minutes from the time the whey protein or control drink is ingested for 120 minutes. Individuals who choose to complete this session will also receive blood sampling for comparison during their session A, every 10 minutes from when they ingest their control/whey protein drink to 30 minutes after their exercise session (total of 120 minutes). Session A represents 'optimal' pre-exercise and exercise duration conditions that match the recommendations. Sessions B and C represent 'sub-optimal' exercise conditions that are still in adherence with exercise guidelines, however these conditions generally confer greater risk of hypoglycaemia than session A. An individual will require a minimum of 48 hours between each exercise session. The meal components will be specific to each participant based on their standard recommendation macronutrient and caloric intake, as determined by their clinician or diabetes educator. Their will be differences between the participants as their standardised meal will be based on individual factors such as; sex, age, average physical activity, etc. As long as the insulin bolus will be administered before the meal the duration of meal consumption does not need to be within a specific time frame rather should be as per standard eating habits. It will be ensured that on the days of these exercise studies that each individual is consistent with their pre-exercise meal caloric and macronutrient composition. Participants will administer their usual pre-lunch insulin bolus, based on their standard carbohydrate counting calculations. If during the exercise sessions the sensor glucose levels drop below 7.0 mmol/L, 10g of carbohydrate will be consumed by the participant and a 15 minute break will be given to allow for a rise in blood glucose. This can be conducted up to three times during the exercise session (totalling 30g of carbohydrate) before the exercise session will be re-scheduled.