Effects of Frequency and Duration of Exercise in People With Type 1 Diabetes A Randomized Crossover Study

According to the Standards of Medical Care in Diabetes by the American Diabetes Association, people with diabetes should aim for 30 minutes of moderate-to-vigorous intensity aerobic exercise at least 5 days a week or a total of 150 minutes per week and doing some type of strength training at least 2 times per week in addition to aerobic activity. However, the effects of different forms and intervals of exercise on glycemic control are not well established. Exercise increases the risk of hypoglycemia both during and several hours after exercise.

There are several strategies to avoid hypoglycemia during exercise. The most common strategy is to reduce insulin and to take carbohydrates before the exercise starts. Short-acting insulin analogs have a duration of approximately four hours, thus reductions need to be planned and done well in advance before the exercise starts. Since different types of exercise (aerobic, strength training or high intensity training) affect blood glucose in different ways and most exercise sessions include a combination of the types, these strategies are often associated with difficulties in obtaining stable blood glucose. The American Diabetes Association guidelines do not explicitly recommend a daily workout routine but outline recommendations for weekly amounts of exercise as there is currently insufficient evidence on the ideal timing, frequency and duration of exercise for preventing hypoglycemia.

Hypothesis: in people with type 1 diabetes, time in hypoglycemia can be reduced if exercise is performed daily over five consecutive days compared to the same total amount of exercise performed at 2 days with at least 2 days interval.

Aim: to evaluate the impact of the same total amount of exercise split into either five consecutive sessions or two sessions with at least 2 days in between on percentage of time spent in hypoglycemia and other glycemic parameters in people with type 1 diabetes.

The participants will go through two interventions: Exercise one session per day for five consecutive days and Exercise one session per day for two days within five days. The exercise session will start with anaerobic (push-ups, back-curls, sit-ups, triceps-dips and jumps) exercise followed by aerobic exercise (moderate intensity of running, walking or cycling). Between the two intervention periods, there will be a wash-out period.

Intervention: 'Exercise one session per day for five consecutive days'. Duration per session: Anaerobic: 4 min, Aerobic: 30 min. Sessions per intervention period: Five. Total duration per intervention period: Anaerobic: 20 min. Aerobic: 150 min. Total: 170 min

Intervention:Exercise one session per day for two days within five days. Duration per session: Anaerobe: 10 min, Aerobe: 75 min. Sessions per intervention period: 2. Total duration per intervention period: Anaerob: 20 min Aerobe: 150 min Total: 170 min

Eligibility Criteria:
Inclusion Criteria:

* Type 1 Diabetes ≥ 2 year
* Insulin pump ≥ 1 year.
* Use of carbohydrate counting and the insulin pump bolus calculator for all meals

Exclusion Criteria:

* Use of anti-diabetic medicine (other than insulin), per oral or injected corticosteroids or other drugs affecting glucose metabolism during the intervention period or within 30 days prior to study start
* Known or suspected alcohol or drug abuse
* Other concomitant medical or psychological condition that according to the investigator's assessment makes the participant unsuitable for study participation
* Females who are pregnant, breast-feeding or intend to become pregnant or are not using adequate contraceptive methods
* Inability to understand the participants' information and to give informed consent
* Chronic use or unable to stop acetaminophen (paracetamol) use
* Allergy to the patch of CGM
* Hypoglycemia unawareness, quantified by Pedersen-Bjergaard
* Severe hypoglycemia within the last year
* Vigorous-intensity exercise for more than 60 minutes on 3 days or more per week