Benefits and Considerations for Exercise with Diabetes

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Benefits and Considerations for Exercise with Diabetes

Jennifer SmithContributor: Jennifer Smith, RD, LD, CDE

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Exercise, physical activity, movement – whatever you call it, we all know that it is important to get on our feet and get our heart pumping and blood flowing regularly.

According to a study done by the Joslin Diabetes Center a few years ago that looked at health and lifestyles of the 50-year medalists (people living type 1 diabetes for more than 50 years), those who got the most activity had reduced risk of cardiovascular disease. Since diabetes is a major risk factor for heart disease and the rate of death from it is 20% higher in those with diabetes than the general public, it makes sense to try to move daily.

Activity makes the muscles of the heart stronger, which means the risk of heart attack and stroke are much lower. It also means there is better circulation of blood and nutrients to the hands and feet, which decreases the risk of neuropathy and potential infection.

Exercise doesn’t have to be aerobic only. Many studies have found strength training to be just as important for building strong bones in kids and helping to maintain bone density and reduce the risk of osteoporosis in adults, especially women after menopause.  Weight training or resistance exercise builds more muscle, which keeps the metabolism running higher all day. The higher our metabolism, the more calories we burn even at rest, which can help to maintain a healthy weight. With diabetes, this increase in muscle mass and higher metabolism helps us maintain our insulin sensitivity, so we respond better to insulin and may use less.  As the study demonstrates, adding more activity on a regular basis can improve short term glucose control, as well as aid with reducing the risk of complications in the future.

Life with diabetes can be stressful, and this is another reason that exercise can be so beneficial to add to your routine regularly. Exercise is a fantastic stress reliever and mood booster due to the wonderful endorphins that are released when you move. Another more recent study looked at how exercise effects things like memory as well as our ability to problem solve and remain productive. Brain activity increases during exercise due to a change in the energy waves that flow through our brain. (Ever find you can work through a problem when taking that long walk?) Since we have so many things to manage with diabetes, it is common to have issues with poor sleep, depression, and burn out. Time and time again, exercise appears to help reduce all of these issues.

Exercise is an all-around healthy habit to add to your routine. However, there is a lot of fear about maintaining blood glucose levels safely during exercise. Learning how to start with adjustment can help you add movement and remove some of that fear. In managing diabetes, we can go forward with healthy caution, but we should not allow diabetes to prevent us from living fully.

To get started with exercise, there are some things to consider to stay safe and enjoy the activity you have planned.

  1. Consider insulin level before you start to exercise. Most people focus on blood glucose levels, but the amount of insulin in the system before heading to exercise is a driving force to show you where glucose levels may go once you get moving.
  2. Exercise after a meal. Reduce the amount of mealtime bolus 25-50% depending on the intensity and duration of the activity planned. Try to get moving within about 90 minutes after your meal to avoid a large blood sugar spike and allow the food with limited bolus to aid with stabilizing blood glucose during the activity.
  3. Evaluate the impact of different exercise on blood glucose levels. Aerobic activity like walking or biking typically causes a drop in blood glucose, but resistance training or weight lifting, as well as high-intensity interval workout, can cause a rise.
  4. Be prepared for a change in sensitivity to insulin. If you are adding exercise after taking some time off from regular movement, expect an increase in sensitivity for the first 1-2 weeks as the body adjusts. Insulin needs may go down as the body becomes more sensitive to insulin.
  5. Expect lower insulin needs overnight. If you exercise in the mid to late afternoon or evening, plan to adjust the basal dose of insulin down 10-25% overnight to avoid lows.
  6. Exercise first thing in the morning in a fasted state. Often people with diabetes have the highest insulin resistance in the morning. If you can get out and move before you eat or take a bolus, it can help you avoid a need to adjust insulin or eat to prevent a drop in blood glucose.
  7. Carry fast acting carb along with you. For every 30 minutes of exercise expect a potential need for 10-15g of carbohydrates if insulin doses haven’t been adjusted before starting to move.
  8. Plan fuel sources. Long duration exercise lasting longer than one hour may require smaller adjustment in the basal dose of insulin to allow for taking in small amounts of food to fuel the muscles without having to bolus.
  9. If you use a continuous glucose monitor (CGM), set alerts for low blood glucose higher than you normally keep them. Getting an alert sooner can help you treat before glucose levels are too low. Glucose readings on CGMs can lag in exercise, so an alert at 70mg/dl could mean you are already lower than that if it occurs during activity.

To make the most of exercise without frustration, find a good diabetes educator. Someone who really understands can be a fantastic resource for tips when starting or adjusting to exercise. They can give you the tips to start well and help you avoid the fear and frustration that may be preventing you from moving more regularly. Contact Integrated Diabetes Services for an appointment to discuss how to make getting more active part of your wellness plan! If you are getting active for the first time, ramping up to improve your performance or trying new things to stay active as you get older, the most important step is the first one!


Jennifer Smith, RD, LD, CDE, holds a Bachelor’s Degree in Human Nutrition and Biology from the University of Wisconsin. She is a Registered (and Licensed) Dietitian, Certified Diabetes Educator, and Certified Trainer on most makes/models of insulin pumps and continuous glucose monitoring systems. She is an active member of the American Diabetes Association and the American Association of Diabetes Educators. She co-authored and published a book on management of type 1 diabetes through pregnancy – Pregnancy with type 1 Diabetes: Your Month-to-Month guide to Blood Sugar Management. She is a contributing author for DiabetesSisters, Insulin Nation and Byron Medical Supply, and has presented at national and international conferences on various topics.

Jennifer has lived with type 1 diabetes since she was a child, is a long distance runner, 70.3 triathlete, and mother of two boys. She works as the Director of Lifestyle and Nutrition for Gary Scheiner at Integrated Diabetes Services, which serves to provide in-depth, real-life education to people with diabetes around the globe. All of this has brought a deeper understanding and first-hand knowledge of the day-to-day events that affect diabetes management and allows her to work seamlessly with clients to achieve their management goals. For more, follow Integrated Diabetes Services on Facebook and using the hashtag #integratedDiabetes