How much a diabetic's blood sugar levels drop in response to physical activity depends on the type of exercise and whether they are male or female, according to a new study. The findings offer a useful guide for diabetics who want to exercise but are wary of low blood sugar.
We all know how good exercise is for our health. However, for people with type 1 diabetes who need to take insulin because their bodies don’t produce enough or any insulin, exercise can cause their blood sugar levels to drop too low, a condition called hypoglycemia. With symptoms including sweating, shaking, irritability, heart palpitations and dizziness, having a ‘hypo’ is not only unpleasant, it can be life-threatening if not treated immediately. So it makes sense for some people with diabetes to stop exercising to avoid the risk of a hypo.
In a new study conducted in collaboration with the Federal University of the São Francisco Valley in Brazil and Staffordshire University in England, researchers investigated which exercises caused the greatest reductions in blood sugar in people with type 1 diabetes.
“This study is important because people with diabetes often lack the motivation to exercise as a means of managing their condition,” says Dr. Pooya Soltani of Staffordshire University, one of the study’s co-authors. “One reason for this is that physical activity can lead to low blood sugar levels, which can cause discomfort and lack of motivation. We investigated whether physical activity could reduce these blood sugar drops.”
Nineteen volunteers with type 1 diabetes, 10 of whom were women, participated in 30 minutes of moderate-intensity aerobic exercise on a treadmill. The researchers tested the effects of interval and continuous exercise by measuring the participants' heart rate, blood pressure and blood sugar before, immediately after and 20 minutes after each session. The researchers also asked the participants to report their rate of perceived exertion and level of enjoyment after each session.
While cardiovascular responses, rates of perceived exertion, and levels of enjoyment were similar across sessions and genders, the researchers observed gender-based differences in blood sugar levels between male and female participants.
Men showed decreases in blood sugar immediately and 20 minutes after continuous aerobic exercise and immediately after interval exercise. In contrast, women showed decreases in blood sugar levels only after continuous exercise at both time points compared to pre-exercise blood sugars. The decreases in blood sugar levels at both time points were greater in men after interval exercise than after continuous exercise. Overall, lower blood sugar levels were seen after continuous aerobic exercise, with greater decreases in men.
The findings suggest that it is important to consider gender-specific differences when prescribing exercise to patients with type 1 diabetes to avoid the risk of hypoglycemia episodes.
“Our study showed that for male patients, interval exercise, such as short bursts of walking, is preferable when starting with low blood sugar levels,” says Dr. Jorge Luiz de Brito-Gomes, from the Federal University of the São Francisco Valley and corresponding author of the study. “In contrast, continuous exercise, such as running, is more suitable for those with higher blood sugar levels to begin with. These approaches may help prevent sudden blood sugar drops.
“For female patients, both intermittent and continuous aerobic exercise appear to be effective starting points,” de Brito-Gomes continued. “We hope these findings indicate that gender-specific recommendations for aerobic exercise prescription should be considered, especially for men with irregular physical activity levels.”
The study was published in the journal: American Journal of Cardiology.
Source: Staffordshire University