What Is Your Intensity? Integrating Different Exercise Intensities Safely When You Are Living With Type 1 Diabetes

You are taking on the challenge of living with type 1 diabetes admirably. You’re eating healthy, you’re monitoring your blood glucose levels, and you have learned (or are learning) to administer the correct dose of insulin. You’ve also incorporated an exercise regimen into your daily or weekly routine.

Exercising has wonderful benefits for our physical and emotional wellbeing. For individuals living with type 1 diabetes, regular exercise has the added benefit of helping you manage your blood glucose.^1,2 However, did you know that various types (or intensities) of exercise can affect blood glucose levels differently?

Defining What Exercise Intensity Means

What does exercise intensity mean? In simple terms it is how hard your body needs to work when performing a certain activity or exercise or the amount of energy your body expends during the exercise. The intensity of an exercise is usually measured by how much your heart rate increases from rest, the effort it takes to breathe, and the amount of exertion experienced. To learn more about how to measure the intensity of exercise, speak to your diabetes healthcare team.

The Triad Of Exercise Intensities

There are generally three different types of exercises based on their intensity level:^2,3

• High intensity exercises
  These are performed by expending bursts of energy within a shorter duration. These types of workouts are often known as anaerobic exercises. Examples are sprinting, boxing and weight training. High intensity exercise increases your heart rate quickly over a short duration, you sweat more, and your breath is laboured to prevent comfortable conversation.
• Moderate-to-low intensity exercises
  These can be performed over a longer duration as it does not utilise energy as intensely and are usually considered aerobic exercises. Some examples are brisk walking, running, biking, water aerobics, and hiking. The difference between low and moderate is the intensity of the workout. A hike through a more difficult, labour-intensive path is more intense than taking a brisk walk around a track. Moderate-to-low intensity increase your heart rate but at a lower and slower pace, your breath is laboured but you can still converse comfortably.
• Mixed intensity exercises
  These are performed by combining exercises high and low-moderate intensity movements. If you observe sports-based activities such as basketball, soccer, and ice hockey you’ll notice they require short bursts of energy mixed in with periods of less intense running/action. Mixed intensity exercises would increase your heart rate quickly during the high-intensity bouts and bring it down again during the low-moderate phase allowing you to catch your breath even though you are continuously moving.

What’s The Relationship Between Exercise Intensity And Its Effect On Blood Glucose?

In individuals living with type 1 diabetes, there are various factors that can affect blood glucose management during and after a workout. These include the blood insulin level, the blood glucose level and the last meal before exercising.¹ The type and duration of exercise can also influence blood glucose levels.

Each type of exercise causes the body to utilise energy and affect blood glucose differently.³ Low-moderate intensity exercises use glucose that is already present in the bloodstream. As the blood glucose is being used as energy during exercise, its level drops.^1,2 High intensity exercises promote the breakdown of glycogen stores in the muscle leading to an increase in blood glucose levels. Mixed activities can cause the levels to shift, causing rising or falling levels.³

Integrating Different Intensity Workouts Into Your Type 1 Diabetes Lifestyle

Checking your blood glucose level and figuring out the amount of insulin in your body (have you just recently administered insulin or not) before starting any workout routine is essential. These will help you decide if you need to have a snack before or even during an exercise routine, and if you need to administer an insulin dose (if the blood glucose level is too high).^1,2

Currently, there are no specific guidelines for different levels of exercise intensities and type 1 diabetes. However, guidelines recommend a total of 150 minutes per week of physical activity with no more than two consecutive days of rest. Resistance exercise should also be incorporated 2-3 times per week.¹

Discuss with your diabetes healthcare team about integrating a workout safely. This should include:^1,2

• Knowing your blood glucose level before exercising.
  Your diabetes healthcare team can guide you on what to do based on the different readings.
• Calculating “insulin on board” (IOB)
  This determines the amount of insulin in your bloodstream to decide if you need a pre-exercise snack and the timing of insulin boluses.
• Planning your pre-exercise meals
  The timing of your last meal before starting your workout will determine the amount of insulin you will need to take.
• Knowing your goal
  Is it to lose weight, train or build muscle? Each would require a different workout regime, type of pre-exercise meal and insulin management.

How Can Using Technology Help You Manage Exercise and Type 1 Diabetes

• Insulin pump therapy has a Temporary Basal Rate feature that allows you to reduce or increase your basal rate before, during and after exercise for up to 24 hours. By adjusting your basal rate, it will help avoid any blood glucose highs or lows that you experience because of exercise.
• Insulin pumps can also tell you how much Active Insulin you have, which can provide you with information on whether you need to have some extra carbohydrate before or during your activity.
• Using CGM (Continuous Glucose Monitoring) systems with insulin pump therapy can provide you with alerts when your sensor glucose level is or is predicted to be high or low.
• Pump and CGM systems have many other features to help you manage highs and lows during exercise. Speak to your diabetes healthcare team to find out what features your system has.

Other ways to support you during your workout routine:^3,4

• Be aware of how you feel and check blood glucose levels during exercise.
• Carry your usual fast-acting hypo treatment with you in case of a low blood glucose level.
• Consider also carrying a carbohydrate containing snack (fruits, crackers, rice cake with peanut butter) with you, especially during extended low-to-moderate exercises.
• Keep a record of the type of activity, blood glucose levels during and after the workout and what you ate/drank to share with your diabetes healthcare team.
• Keep hydrated by drinking plenty of water.

Final Thoughts

Exercising has incredible benefits and knowing how to navigate the different intensity workouts is essential before you start any fitness routines. Though some additional steps are needed to ensure you exercise safely, always remember that routines form habits, making them easier to handle!

Reference

1. Riddell MC, Wallen IW, Smart CE, et al. Exercise management in type 1 diabetes: a consensus statement. Lancet Diabetes Endocrinol. 2017 Available online: http://dx.doi.org/10.1016/S2213-8587(17)30014-1. (Accessed March 2022).
2. Diabetes.org.uk. Sport nutrition and type 1 diabetes. https://www.diabetes.org.uk. 2021 Available at: https://www.diabetes.org.uk/guide-to-diabetes/enjoy-food/eating-with-diabetes/out-and-about/sports-nutrition-and-type-1-diabetes. (Accessed March 2022).
3. JDRF.org. Different types of exercise and how they affect type 1 diabetes.https://www.jdrf.org. 2021 Available at: https://www.jdrf.org/t1d-resources/living-with-t1d/exercise/exercise-impact/. (Accessed March 2022).
4. National Health Service (UK). Exercise and sport.https://www.nhs.uk . 2021 Available at:https://www.nhs.uk/conditions/type-1-diabetes/exercise-and-sport/ . (Accessed March 2022).