New Guidelines for Exercising with Type 1 Diabetes (T1D)

Are you thinking about running a half marathon? Do you hit the gym a few times per week or like to go for long hikes on weekends?

Whatever your favorite activity, it can require some adjustment to your usual diabetes management plan.  A new set of guidelines was recently published in the medical journal, Lancet, by an international task force of experts on the science of exercise. These guidelines help better define treatment strategies to keep you healthy, safe and fit.

Amanda Kirpitch, MA, RD, CDE, a diabetes educator at the Berrie Center with a special interest and expertise in exercise, reviewed the new guidelines and identified a few key points that may help you fine-tune your plan. What follows is her takeaway:

The type of activity you do may matter: As a general rule, when you do a cardio type workout (walking, running, riding a bike, playing in the yard with your kids), the activity helps your muscles use glucose without insulin. This means that if you don’t change anything about your current regimen, you may have hypoglycemia (a low glucose level).  It is advised to lower your insulin or increase the carbohydrates you are eating around the time of activity.

Strength-training activities, such as High-Intensity Interval Training (HIIT) may cause a rise in glucose towards the end of the activity period.  This is the due, in part, to an increased release from the liver due to a stress response.

After most forms of activity, you may experience hypoglycemia hours after the workout and/or overnight. This is due to the continued effects of trained muscles that are capable of doing a better job of utilizing glucose.

Data is available showing that you may be able to prevent lows in cardio workouts by engaging in strength activity first. The strength activity seems to have a protective effect against hypoglycemia lasting throughout the aerobic workout.

Insulin Timing is Important: If your workout is planned, you will have more options for adjustments than if the activity is more spontaneous. In either case, it is good to consider if you have insulin “on board,” taken to cover a prior meal or to correct a high blood sugar. If you do, you want to ensure that the adjustments you make for activity (having a snack, reducing insulin via insulin pump) take this insulin into account. 

Where you inject your insulin can also be a factor: If you are going to go for a run, and you administered insulin onto a site on your leg within 3 hours of your run, you may find that your insulin will work a bit harder than you might expect. It is best to use injection sites that will not be used during exercise if possible.

What you can do: The best way to assess your response to activity is to keep good records. You should check before, during and after the workout, especially if it lasts longer than 30 minutes. 

Then consider meeting with your diabetes educator for help to individualize your insulin regimen. The Berrie Center also offers a quarterly Exercising with T1D class to review information and answer questions. Check the online calendar for class information and to register.