Takeaways

• Individuals with diabetes should engage in regular physical activity—both aerobic and resistance training—for optimal health and wellbeing.

• You can lower your risk of sustaining injuries when exercising by starting slow, working at an appropriate intensity, warming up before, then cooling down after.

• Signs you should stop exercising include feeling faint, nauseated, chest tightness or pain, and loss of muscle control.

• Exercise prescriptions should be tailored to meet your specific needs.

• A health professional could coordinate your medication, meals, and workouts to keep your blood sugar in a safe range.

When done safely, exercise can be a valuable aid in controlling blood sugar levels and maintaining optimal health. However, there are some exercise precautions which people with diabetes must take. This article highlights the special considerations for someone with diabetes, how to prevent injuries and precautions one should take when exercising while on diabetes medication. Read our other article for an introduction to exercise for individuals with diabetes.

Preventing injuries

Don't try to do too much too soon: Gradually increase the amount of time or distance of your activity by about 10 percent each week. For example, if you started with 60 mins this week, aim for around 65 mins of exercise the next week. It won't seem like much at first, but it can add up quickly.

Warm up and cool down: Start out slowly and give your heart and muscles a chance to get going. When you're finished with your activity, take a few moments to slow down before stopping completely.

Don't work too hard: If you’re just starting and the activity feels too hard, it might not be suitable for you. Slow down until you feel comfortable. You should aim to work at an intensity which is somewhat uncomfortable, but not to the extent that you are out of breath most of the time.

Special considerations

While everyone can benefit from regular physical activity, some people may need to take extra precautions. If you have special health concerns, ask your doctor to help you find an exercise plan that's right for you. If you feel any of the following while you're exercising, slow down gradually and then stop:

• Faint or dizzy

• Nauseated

• Chest tightness or pain

• Extremely short of breath

• Loss of muscle control

Blood glucose responses are impacted by the type, timing, intensity, and duration of exercise, as well as by many other factors. Different activities will likely require individualized adjustments to carbohydrate and food intake and insulin dosing during and after exercise.

In general, aerobic exercise is associated with reductions in glycaemia, whereas anaerobic exercise might be associated with a transient increase in glucose concentrations. Both forms of exercise can cause delayed-onset hypoglycemia in recovery.

Precautions if you are on medicines for diabetes

For aerobic exercise, reductions in insulin administration before the activity can help ameliorate the risk of hypoglycaemia. Similarly, you may ingest some carbohydrates to maintain your blood sugar levels during exercise, though the amount may vary depending on your pre-activity blood sugar levels. For anaerobic exercise, conservative insulin dose corrections might be required if you tend to experience an increase in glucose level during the activity. In all instances, additional vigilance around glucose monitoring is needed before, during, and after the physical activity.

Below are some general guidelines for your pre-exercise blood sugar levels. The measurements are expressed in milligrams per deciliter (mg/dL) or millimoles per liter (mmol/L).

• Lower than 100 mg/dL (5.6 mmol/L). Your blood sugar may be too low to exercise safely. Eat a small snack containing 15 to 30 grams of carbohydrates, such as a fruit or fruit juice, crackers or even glucose tablets before you begin your workout. Ensure your blood sugar level is above 100mg/dL prior to starting your work-out.

• 100 to 250 mg/dL (5.6 to 13.9 mmol/L). You're good to go. For most people, this is a safe pre-exercise blood sugar range.

• 250 mg/dL (13.9 mmol/L) or higher. This is a caution zone — your blood sugar may be too high to exercise safely. Before exercising, test your urine for ketones — substances made when your body breaks down fat for energy. The presence of ketones indicates that your body doesn't have enough insulin to control your blood sugar.

It is important to note that special exercise considerations may apply to individuals with the following complications. Consult your doctor before you start exercising if you have any of these conditions:

• Uncontrolled blood glucose levels – high or low

• Uncontrolled high blood pressure

• Unstable heart conditions

• Retinopathy (eye and sight condition)

• Peripheral neuropathy (nerve damage to extremities, foot ulcers etc)

• Autonomic neuropathy (nerve damage to internal organs)

• Microalbuminuria and nephropathy (poor kidney function)

Takeaway

Regular physical activity should be a routine objective for patients with diabetes, for various health and fitness reasons. To support your overall health and well-being, take part in regular exercise, including aerobic and resistance activities. However, it is good to note that specific recommendations and precautions may apply, and will vary by age, activity done, and your current health state. Exercise prescriptions should be tailored to meet the specific needs of each individual. 

Consult your doctor and health coach to help you learn how to coordinate your medication, meals, snacks, and workouts to keep your blood sugar in a safe range before you get started.

For more information about the management of diabetes, check out our diabetes resource hub and our health library for articles related to diabetes!