Diabetes is not a single condition, it is multiple metabolic syndromes that share a common defining feature; an inability of the body to control blood sugar levels. There are three main types of diabetes, type 1, type 2 and gestational diabetes. Risk factors, the average age of onset and treatment approaches may all vary across the different types of diabetes, but one thing that is constant across all forms is the benefits that can be gained from undertaking regular exercise.
Most of the studies that have looked at the benefits of exercise with regards to diabetes management have investigated aerobic and/or resistance training. Aerobic exercise involves repeated, continuous movements utilising the large muscle groups. It is usually moderate to high intensity and is also referred to as cardio training. Resistance training is a means of building up strength. It uses some form of resistance (most commonly, free weights, resistance bands or a person’s own body weight), to induce the muscles to contract. There is some evidence that regular stretching and yoga-type activities can also be beneficial.
Type 1 Diabetes
Type 1 diabetes is usually diagnosed during childhood. The body is unable to produce insulin so people with the condition require daily injections of insulin to regulate their blood sugar levels. There is currently no cure for type 1 diabetes and adopting lifestyle changes, such as regular exercise, will not make the condition go away. However, remaining physically active can improve your overall health.
Regular, moderate exercise has a significant effect on acute and chronic glycaemic control. There have been insufficient studies to determine the optimal type of exercise, however, aerobic training has been shown to improve cardiorespiratory fitness and reduce insulin resistance. People with diabetes are at risk of experiencing hypoglycaemic events; however, brief periods of high intensity exercise can minimise this risk. There is also an overall reduction in mortality rates in those patients who undergo regular physical activity. The data is less well defined with regards to resistance training. Performed in combination with aerobic exercise, it likely has a beneficial effect, but the scientific evidence for it is limited.
Of course, patients with type 1 diabetes need to remain aware of their blood sugar levels both before and after exercise. Most beneficial effects are observed when exercise is undertaken in the postprandial period (1-3 hours after consuming a meal). However, if blood sugar levels fall below 100mg/dL or rise above 250mg/dL additional care is warranted and stabilisation of levels should be obtained before exercise commences.
Type 2 Diabetes
Far more common than the type 1 form of the condition, type 2 diabetes mellitus (T2DM) is diagnosed when the body struggles to make sufficient, good quality insulin. It can arise at any age, but is most often seen in middle-aged adults with a high BMI. The rising obesity rates across the developed world are leading to significantly more diagnosed cases of T2DM. Whilst medications can help to control the symptoms of T2DM, most doctors also appreciate the value of encouraging their patients to implement lifestyle changes to help manage the condition. It is even thought that with significant weight loss, T2DM might be driven into remission.
Performing aerobic exercise, resistance training, or a combination of the two has been shown to have a small to moderate beneficial effect on glucose control. In fact, the benefits are enhanced by taking a combination approach and incorporating both elements into a workout. Experts recommend a minimum of 30 minutes of aerobic exercise each day to enhance insulin action, and 2-3 sessions of resistance training per week, on non-consecutive days.
Those who are classed as pre-diabetic have blood glucose levels above the normal range and are at high risk of developing T2DM. If people who fall into this category undertake 150 minutes of physical activity a week, alongside making dietary changes, their risk of T2DM is reduced by between 40 and 70%.
Gestational diabetes (GDM) is usually diagnosed between weeks 24 and 28 of pregnancy. Greater weight gain during pregnancy is associated with an increased risk of GDM, as is leading a sedentary lifestyle. In contrast, partaking in moderate exercise, such as brisk walking, during early pregnancy, can protect against the later development of GDM. GDM can be dangerous for both the mother-to-be and her unborn child, therefore, it is very important to implement preventative measures from early on in a female’s pregnancy. Furthermore, women with GDM are at increased risk of developing T2DM and, thus, longer term lifestyle adjustments should be considered for the time that follows the gestation period.
Doctors recommend that pregnant females partake in 20-30 minutes of moderate exercise per day. Clearly, not all exercises are appropriate; contact sports and those with a risk of falling should be avoided. However, recreational physical activity is strongly recommended. Aerobic and resistance training can both be performed safely during pregnancy, but participants should avoid prolonged periods of high temperatures, or excessive fluid loss through sweating.
Exercise has many benefits; it lowers blood glucose levels and increases the body’s sensitivity to insulin, meaning that it can be a very useful tool in the management of diabetes. It is also an effective means of losing weight and a natural mood enhancer and stress reliever; thereby improving quality of life in those with a long-term chronic condition, such as diabetes.
Taking part in regular physical activity improves the health of those with type 1 diabetes. It can also be used to prevent, or at least delay, the development of T2DM in those who are considered to be high risk. The use of exercise as part of the treatment approach for any form of diabetes is widely accepted and encouraged.
- Colberg, Sheri R., et al. “Physical Activity/Exercise and Diabetes: A Position Statement of the American Diabetes Association.” Diabetes Care, vol. 39, no. 11, Nov. 2016, pp. 2065–2079., doi:10.2337/dc16-1728.
- Harvard Health Publishing. “The Importance of Exercise When You Have Diabetes.” Harvard Health, https://www.health.harvard.edu/staying-healthy/the-importance-of-exercise-when-you-have-diabetes.
- Helmrich, Susan P., et al. “Physical Activity and Reduced Occurrence of Non-Insulin-Dependent Diabetes Mellitus.” New England Journal of Medicine, vol. 325, no. 3, 18 July 1991, pp. 147–152., doi:10.1056/nejm199107183250302.
- Mccombie, Louise, et al. “Beating Type 2 Diabetes into Remission.” Bmj, vol. 358, 13 Sept. 2017, doi:10.1136/bmj.j4030.
- Padayachee, Cliantha, and J S Coombes. “Exercise Guidelines for Gestational Diabetes Mellitus.” World Journal of Diabetes, vol. 6, no. 8, 25 July 2015, pp. 1033–1044., doi:10.4239/wjd.v6.i8.1033.
- Snowling, N. J., and W. G. Hopkins. “Effects of Different Modes of Exercise Training on Glucose Control and Risk Factors for Complications in Type 2 Diabetic Patients: A Meta-Analysis.” Diabetes Care, vol. 29, no. 11, Nov. 2006, pp. 2518–2527., doi:10.2337/dc06-1317.
- Tonoli, Cajsa, et al. “Effects of Different Types of Acute and Chronic (Training) Exercise on Glycaemic Control in Type 1 Diabetes Mellitus.” Sports Medicine, vol. 42, no. 12, 1 Dec. 2012, pp. 1059–1080., doi:10.2165/11635380-000000000-00000.
- “What Is Diabetes?” National Institute of Diabetes and Digestive and Kidney Diseases, U.S. Department of Health and Human Services, 1 Dec. 2016, https://www.niddk.nih.gov/health-information/diabetes/overview/what-is-diabetes.