Lifestyle changes are hard. Many type one diabetics lead sedentary lives. They have a big fear of hypoglycaemia from exercise. Another complaint is that they don’t have enough time. High intensity interval training has been gaining popularity over the last few years due to its low time commitment. HIIT improves vascular function without the reductions in blood sugar that are often associated with moderate intensity exercise.
One study looked at what happened at home. Eleven type 1s completed six weeks of HIIT at home. A session was one minute of HIIT followed by one minute of rest. The goal was to get to 80% or more of their predicted maximum heart rate from the formula 220- age. The exercise component was two thirty second body weight exercises with no rest in between. There were 18 exercises and 9 suggested pairings but the participants were allowed to choose what they did of these exercises. They were to exercise on three days of the week, starting at six minutes and building up by two sessions every two weeks. They had heart rate monitors that could be downloaded so they and the researchers could see their results. They were to exercise only when their blood sugar was between 7 and 14 mmol/L.(126-252mg/dL). Blood sugars, insulin and ingested carbohydrates were measured.
Adherence was 95% and pulse targets were achieved. Glucose levels remained the same during and one hour after exercise. Carbs were ingested in 6% of the sessions. Insulin was needed after only 3 of the 188 sessions. There was no severe hypoglycaemic episodes. After six weeks there was a mean decrease of 13% in their daily short acting insulin doses. There were no significant changes to the mean blood glucose concentration or to BMI.
Home exercise means that there is no commute or gym fees. It was a bit sad that there was no weight loss despite the strict adherence to the regime by these motivated participants.
The top three barriers to exercise in type 1s are given as lack of time 91%, fear of hypos 27%, and a lack of motivation 18%, so these quick, high intensity exercise sessions can provide a solution to these barriers. It is convenient, quick, requires no equipment, does not adversely affect blood sugar levels and can increase motivation to exercise. It only took 60 minutes a week overall.
Practice pearls:
HIIT at home is quick and does not need gym attendance.
HIIT is good for busy people taking an hour a week.
HIIT reduces short acting insulin doses.
HIIT does not cause significant hypos, but blood sugar levels should still be checked.
HIIT sadly does not cause weight loss.
Scott Sam N et al. A multidisciplinary evaluation of a virtually supervised home based high intensity interval training intervention in people with type one diabetes. Diabetes Care. ADA. 1 Dec 2019.
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