Beat it

Beat it

Examining the role of exercise in managing and preventing diabetes


Lia Steakley

More than 29 million adults and children in the United States are living with diabetes, and it’s estimated (.pdf) that an additional 86 million Americans ages 20 years or older have prediabetes, putting them at increased risk of developing the disease.
The good news is that lifestyle modifications can be an effective method for managing or preventing diabetes. In recognition of National Diabetes Month, I reached out to Baldeep Singh, MD, a clinical professor at Stanford who focuses on chronic disease management, to discuss the importance of regular physical activity for patients diagnosed with diabetes and those working to limit their risk of developing the disease. This Thursday, Singh will explore the topic more in-depth during a Stanford Health Library event at the Arrillaga Alumni Center on campus, where attendees can also have their blood glucose checked. The discussion will also be webcasted for those unable to attend in person.
In this Q&A, Singh highlights scientific evidence showing that staying active has a beneficial effect on insulin sensitivity, and discusses the potential of exercise, in combination with other behavioral changes, to induce partial, or full, remission of type 2 diabetes.
How does regularly exercising help in preventing or delaying type 2 diabetes?
The benefit of exercise in preventing diabetes has been demonstrated in several studies. A meta-analysis of 10 studies of physical activity and type 2 diabetes reported a lower risk of developing diabetes with regular moderate physical activity, including brisk walking, compared with being sedentary
Additionally, in a subsequent prospective cohort study in men, either weight training or aerobic exercise for at least 150 minutes per week was associated with a lower risk of developing type 2 diabetes compared to those with  a control group who did no physical activity.
Why is engaging in physical activity important in managing type 2 diabetes?
In patients with type 2 diabetes, studies show that short-term exercise training improves insulin sensitivity just as it does in non-diabetics. In patients with type 2 diabetes treated with medication, exercise tends to lower blood glucose concentrations.
Exercise improves glycemic control in patients with type 2 diabetes, as illustrated by the findings of several meta-analyses of trials examining the effect of exercise on glycemic control in patients with type 2 diabetes. Exercise training reduces glycosylated hemoglobin (A1C) values by approximately 0.5 to 0.7 percentage points compared with control participants.
A 2013 study showed that walking 15 minutes after every meal was an effective approach to controlling blood sugars. Are short bouts of exercise throughout the day more effective than longer periods of physical activity spaced throughout the week?
Some form of regular exercise is likely to be beneficial in most patients with diabetes, even those with advanced, long-standing disease. We encourage patients with diabetes to perform 30 to 60 minutes of moderate-intensity aerobic activity on most days of the week. We tell patients choose a type of exercise he or she will enjoy.
A reasonable initial regimen is 10 minutes of stretching and warm-up, followed by 20 minutes of gentle aerobic exercise such as walking, cycling, or rowing. The exercise should be performed regularly (at least three to five times per week) and preferably at the same time in relation to meals and insulin injections in patients treated with insulin.
The American Heart Association, the American Diabetes Association, and the American College of Sports Medicine recommend at least 150 minutes of moderate-intensity aerobic activity per week for patients with diabetes. The activity should be distributed over at least three days each week, with no more than two consecutive days of inactivity.
Another study recently published found that exercise provided less protection against diabetes in individuals at high genetic risk for diabetes and insulin resistance. Do genetics trump exercise, or other lifestyle factors, when it comes to risk for diabetes?
In contrast to the response in type 2 diabetes, there is less evidence that regular exercise is associated with improved glycemic control in patients with type 1 diabetes, presumably due to the lesser importance of insulin resistance in these patients. Therefore we can conclude the same with more genetic forms of type 2 diabetes. However, even if the glycemic control is not as good the cardiovascular and other health benefits of regularly exercising are clear.
Can regular exercise, combined with other lifestyle changes, induce partial, or full, remission of type 2 diabetes?
While there are many factors involved, remission is possible for patients with mild diabetes who make big lifestyle changes. Either way, exercising will allow you to better control your diabetes, require less medication and reduce the long-term health risks of diabetes.