Exercise to regulate blood sugar and improve fitness

Managing blood glucose levels is the number one goal for people with diabetes. Exercise interventions lasting eight weeks or longer have been shown to reduce levels of haemoglobin A1c (HbA1c), a marker of long-term blood glucose control, in people with type 2 diabetes. In addition, exercise improves cardiovascular fitness and can help to preserve mobility in people who are overweight and have diabetes.

Aerobic exercise has long-established benefits in helping to reduce diabetes risk and diabetes complications, but the new standards point out that adding weight training to your exercise programme could increase these gains. Weight training as a stand-alone intervention has been found to reduce HbA1c levels in older adults with type 2 diabetes, and exercise programmes that combine aerobic and weight training exercise have been found to have more HbA1c-lowering effects in adults with diabetes than either type of exercise alone.

How much exercise is enough?

“Exercise has been shown to improve blood glucose control, reduce cardiovascular risk factors, contribute to weight loss, and improve well-being,” the authors of the standards said.

Here are the US Department of Health and Human Services' exercise guidelines described in the standards:

• Aerobic exercise. Most adults with diabetes should engage in moderate-intensity aerobic exercise for at least 150 minutes per week, or vigourous-intensity aerobic exercise for at least 75 minutes per week, spread over at least three days with no more than two days in a row without exercise.
• Weight training. Adults with diabetes should engage in muscle strengthening activities on at least two nonconsecutive days per week. Each session should include five or more sets of resistance exercises engaging different groups of muscles so all the major muscle groups are strengthened.
• Sedentary time. All individuals, including those with diabetes, should limit time spent in sedentary activities and interrupt extended periods of sitting by briefly standing or walking every 30 minutes.
• Do what you can. If you have a condition that limits your ability to exercise, it is still important to get physical activity in any amount that matches your ability. Flexibility and balance training two to three times per week are particularly important for those aged 65 and older, whether or not they have diabetes.
• Getting started. Starting with short periods of low-intensity exercise and gradually increasing both the intensity and duration is the best approach for people with a high risk of cardiovascular disease. Consult with your doctor to develop an exercise programme that takes into account your age, fitness level, and health.

Another reminder to exercise, eat well, and manage weight

Obesity, especially abdominal obesity, and insulin resistance (when insulin no longer works efficiently to control blood sugar levels) are the most important components of metabolic syndrome—a cluster of conditions, such as high blood pressure and large waistline, linked to an increased risk of diabetes and heart disease. Scientists are still working out the causes, but ways to reduce your risk and help address metabolic syndrome are well established:

• Lose weight. If you are overweight, set an initial goal of losing 7% to 10% of your current body weight, with a long-term goal of sustaining a 5% to 7% weight loss.
• Examine eating patterns. Eat a diet low in sugars and refined grains, and high in vegetables, fruits, whole grains, pulses, and nuts and seeds.
• Exercise. The evidence strongly supports the positive role of exercise in improving blood sugar control and reducing heart disease and diabetes risk. Following the guidelines set out in the 2017 Standards of Medical Care in Diabetes will help ensure long-term health.

(Diabetes Care 2017;40:S36–S58)