This study compares aerobic exercise training performed before breakfast (i.e., in the fasted state) to similar training performed after breakfast in people with type 1 diabetes. Training will take place over 12 weeks.
People with type 1 diabetes (PwT1D) are encouraged to increase their physical activity (PA). Increasing the amount of PA can be difficult, especially for PwT1D who experience barriers to exercise. Therefore, simply recommending that PwT1D preform more exercise may not be the most effective prescription in the long term. Recent short-term studies have s suggest that exercise performed before eating (fasted) causes blood sugars to decrease less or even increase, compared exercise performed after a meal, which usually causes blood sugar to decrease. To date, no long-term study has compared the effects of exercise performed with or without eating beforehand in people with T1D. This study will compare the effects of 12 weeks of exercise before breakfast compared to 12 weeks of exercise after breakfast. It is expected that exercise before breakfast (i.e., in the fasted state) will lead to larger reductions in overall insulin dose, without the addition of more exercise.
Study Type
INTERVENTIONAL
Allocation
RANDOMIZED
Purpose
TREATMENT
Masking
SINGLE
Enrollment
20
Participants will complete three sessions of combined resistance-aerobic exercise per week. Sessions will always start with resistance training followed by aerobic training, and will increase in duration throughout the intervention period, so that by the final three weeks of the intervention, all participants accumulate 150 minutes per week of moderate intensity aerobic exercise and 75 minutes of resistance exercise per week. Participants will complete three distinct resistance exercise sessions per week, which will increase in load, but decrease in repetition range throughout the trial. The aerobic component of the exercise sessions will increase in duration from 35 to 50 minutes per session. Participants will walk on a treadmill at a speed and incline that corresponds to 70-80% of ventilatory threshold.
Participants will complete three sessions of combined resistance-aerobic exercise per week. Sessions will always start with resistance training followed by aerobic training, and will increase in duration throughout the intervention period, so that by the final three weeks of the intervention, all participants accumulate 150 minutes per week of moderate intensity aerobic exercise and 75 minutes of resistance exercise per week. Participants will complete three distinct resistance exercise sessions per week, which will increase in load, but decrease in repetition range throughout the trial. The aerobic component of the exercise sessions will increase in duration from 35 to 50 minutes per session. Participants will walk on a treadmill at a speed and incline that corresponds to 70-80% of ventilatory threshold.
University of Alberta
Edmonton, Alberta, Canada
RECRUITINGDaily insulin dose (units/kg/day)
Total daily insulin dose (including basal and bolus insulin) will be measured over 7 consecutive days.
Time frame: From enrolment to the end of the exercise intervention at week 12.
Continuous glucose monitoring
24-hour mean glucose (mmol/L) as measured by continuous glucose monitors.
Time frame: From enrolment to the end of the exercise intervention at week 12.
Continuous glucose monitoring
Time in range (%) as measured by continuous glucose monitors.
Time frame: From enrolment to the end of the exercise intervention at week 12.
Magnetic resonance imaging (MRI) volumes
MRI derived volumes (e.g., muscle fat, hepatic fat, pancreatic fat, subcutaneous fat, visceral fat)
Time frame: From enrolment to the end of the exercise intervention at week 12.
Basal and bolus insulin dose (units/kg/day)
Basal insulin dose (units/kg/day), bolus insulin dose (units/kg/day), and basal to bolus ratio
Time frame: From enrolment to the end of the exercise intervention at week 12.
Bioelectrical impedance (BIA) in kilograms
BIA body composition outcomes (e.g., fat mass, fat free mass, total body water), all measured in kilograms
Time frame: From enrolment to the end of the exercise intervention at week 12.
Glycated haemoglobin (%)
Hlycated hemoglobine (also known as HbA1c) expressed as a percentage.
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Time frame: From enrolment to the end of the exercise intervention at week 12.
Concentrations of Fasting glucose
Plasma glucose measured after an overnight fast
Time frame: From enrolment to the end of the exercise intervention at week 12.
Concentrations of Fasting insulin
Plasma insulin measured after an overnight fast
Time frame: From enrolment to the end of the exercise intervention at week 12.
Concentrations of Fasting lipids
Plasma total cholesterol, HDL-Cholesterol, LDL-Cholesterol and Triglycerides measured after an overnight fast
Time frame: From enrolment to the end of the exercise intervention at week 12.
Aerobic fitness
Exercise test to determine ventilatory threshold
Time frame: From enrolment to the end of the exercise intervention at week 12.
Body weight (kilograms)
Weight will be measured in kilograms
Time frame: From enrolment to the end of the exercise intervention at week 12.
Height (centimeters)
Standing height
Time frame: From enrolment to the end of the exercise intervention at week 12.
Waist circumference (centimeters)
Waist circumference (between 12 rib and iliac crest) measures in centimeters
Time frame: From enrolment to the end of the exercise intervention at week 12.
Hip circumference (centimeters)
Hip circumference (between 12 rib and iliac crest) measures in centimeters
Time frame: From enrolment to the end of the exercise intervention at week 12.
Physical Activity in minutes per day
Accelerometer measured active time (min/day), sedentary time (min/day)
Time frame: From enrolment to the end of the exercise intervention at week 12.
Food logs (kilocalories)
Food logs will be completed for three days (two weekday and one weekend) for estimation of macronutrient intake and total energy intake. Each of these will be expressed as kilocalories (i.e., kcal).
Time frame: From enrolment to the end of the exercise intervention at week 12.
Feasibility (rates expressed as percentage of the total sample)
Feasibility will include recruitment rate, and dropout rate. Each rate will be reported as the percentage of the total sample.
Time frame: From enrolment to the end of the exercise intervention at week 12.
Feasibility (rates expressed as percentage of the total number of sessions)
Feasibility will also include exercise adherence. Adherence will be reported as the percentage of the prescribed exercise sessions that were completed).
Time frame: From enrolment to the end of the exercise intervention at week 12.
Feasibility (barriers)
Barriers will bve assessed using the "Barriers to Physical Activity in Type 1 Diabetes" (BAPAD-1) scale. This is a 11-item scale with 7-point Likert-type questions (i.e., each question has a minimum of 1 and a maximum of 7). The maximum score is therefore 77 and minimum score 11. A higher score indicates greater barriers.
Time frame: From enrolment to the end of the exercise intervention at week 12.