An estimated 30 million Americans are living with diabetes today, and public health experts predict that one in three Americans will have diabetes by 2050 (CDC, 2014). Common diabetes symptoms include frequent urination, increased thirst and hunger (even when eating and drinking regularly), feeling tired, blurry vision, cuts and bruises that heal slowly, unexplained weight loss, and tingling, pain or numbness in the hands or feet (ADA, 2018).
Diabetes is diagnosed by a physician using one of the following blood tests (American Diabetes Association, 2016):
- Fasting Plasma Glucose (FPG) Test – This test requires fasting for 8-10 hours prior to testing. A small blood sample is collected and measured for glucose concentration. A reading of 100 mg/dL or more is considered pre-diabetes. A level of 126 mg/dL or more is indicative of diabetes.
- Oral Glucose Tolerance Test (OGTT) – An OGTT requires the patient to consume a concentrated glucose mixture. Blood is drawn two hours later, and blood glucose levels are measured. A level of 140 mg/dL or more indicates prediabetes, and 200 mg/dL or more indicates diabetes.
- A1C or Glycosylated Hemoglobin Test (HbA1C) – HbA1C gives the average value of a person’s blood glucose levels over a two- to three-month period. Hemoglobin is the part of a red blood cell that carries oxygen and sometimes joins with the glucose in the bloodstream. Diabetes is diagnosed at an A1C of greater than or equal to 6.5%. An A1C of 5.7-6.4% may mean a person is at an increased for having diabetes and is often classified as prediabetes.
Early detection and treatment can help to reduce the risk of diabetes-related complications such as organ damage, heart disease and diabetic eye disease. Exercise is key in both the prevention and management of diabetes. Here are four important considerations for designing safe and effective exercise programs for clients with diabetes.
1. Daily exercise is ideal.
People who have diabetes are encouraged to follow current Physical Activity Guidelines for Americans, which include:
- A minimum of 150 minutes of moderate-intensity aerobic physical activity every week, or 75 minutes of vigorous-intensity aerobic physical activity, or a combination of moderate and vigorous-intensity physical activity
- Muscle-strengthening activities that include all major muscle groups at least two or more days a week (S. Department of Health and Human Services Office of Disease Prevention and Health Promotion, 2018)
All adults are encouraged to be physically active on most days of the week, but daily physical activity is especially beneficial for people with diabetes. The American College of Sports Medicine (ACSM) recommends no more than two consecutive days of inactivity for people with diabetes because regular physical activity can help to stabilize muscle and liver insulin action (ACSM, 2018). Furthermore, while all activity is beneficial, programs that combine both resistance and aerobic exercise improve glycemic control better than either type of training performed alone (Colberg et al., 2016).
2. Prolonged sedentary behavior should be avoided.
In addition to regular physical activity, it is import to avoid prolonged periods of sedentary behavior. Americans have become so sedentary during both work and leisure time that prolonged sedentary behavior is now recognized as an independent risk factor for cardiometabolic disease and premature death (Owen et al., 2010). Even regular exercisers are not exempt. We all need to reduce time spent sitting and in other sedentary behaviors to reduce the risk of chronic disease. For people with type 2 diabetes, and among those at risk for the condition, excessive sedentary time is associated with reduced glycemic control. However, intermittent bouts of light activity—even as little as 5 minutes—performed every 20-30 minutes has been shown to improve glycemic control (Colberg et al., 2016).
3. Physical activity carries unique health risks for people with diabetes, but complications can be mitigated with proper planning.
People with diabetes have a higher risk of acute exercise complications such as cardiac events, hypoglycemia (low blood sugar) and hyperglycemia (high blood sugar) (National Institutes of Health and National Institute of Diabetes and Digestive and Kidney Diseases, 2018). Asymptomatic individuals whose diabetes is under control will probably not require any special pre-exercise testing. However, individuals who are symptomatic, and those identified as higher-risk, should be referred to their healthcare providers before beginning a new exercise program and before participating in high-intensity exercise activities.
4. Special care should be taken to prevent foot problems.
Individuals who have diabetes are more prone to foot problems due to nerve damage and poor blood flow from high glucose levels. Encourage these clients to wear comfortable and supportive shoes. Additionally, the feet should be checked for sores and blisters before, during and after physical activity so that these types of breaks in the skin may be promptly recognized and addressed.
Multimodal approaches are needed to successfully manage diabetes. Diet, exercise and, for many, medication are all important pieces to the puzzle. As a health and exercise professional, you have the ability to help clients with diabetes achieve better health and disease control. Physician directives should always be followed and some clients may need additional support from other health professionals such as a dietitian or certified diabetes educator. Learn more about preventing and managing diabetes at www.diabetes.org.
American College of Sports Medicine (2018). ACSM’s Guidelines for Exercise Testing and Prescription, 10th edition. Philadelphia: Wolters Kluwer.
American Diabetes Association (2018). Diabetes Symptoms.
American Diabetes Association (2016). Diagnosing Diabetes and Learning about Prediabetes.
Centers for Disease Control and Prevention (2014). National Diabetes Statistics Report.
Colberg, S.R. et al. (2016). Physical activity/exercise and diabetes: A position statement of the American Diabetes Association. Diabetes Care. 39, 2065-2079.
National Institutes of Health and National Institute of Diabetes and Digestive and Kidney Diseases (2018). Diabetes Diet, Eating and Physical Activity.
Owen, N. et al. (2010). Sedentary behavior: Emerging evidence for a new health risk. Mayo Clinic Proceedings, 85, 12, 1138-1141.
U.S. Department of Health and Human Services Office of Disease Prevention and Health Promotion (2018). Physical Activity Guidelines Advisory Committee Scientific Report.