Creating a plan to help keep your blood sugar in a safe zone while being active
Exercise has always been tricky for me. Even taking my dog for a walk around the block can cause a 50-100 mg/dL drop in my blood sugar (BG). So when I was interested in taking a Zumba class at my gym, I had to come up with a game plan to make sure I stayed safe and able to do the full class.
Using the right tools
First, a really important tool I use during exercise is a continuous glucose monitor (CGM). Getting a BG reading every 5 minutes (technically it’s measuring the sugar in the interstitial fluid) along with a trend of blood sugar helps me gauge when I need to react to prevent a low BG. There have been many times when BG was dropping quickly or when I could not feel that my BG was low (hypoglycemia unawareness) during exercise. If it hadn't been for CGM picking up the fast changes in BG, I could have gotten into a dangerous situation.
Pictured to the left is me on a paddle Board at Lost Lake wearing the Dexcom CGM. Yes, I do have a funny tan after that, but it was worth it to be able to paddle safely. (I am very close to shore in this photo and stayed close to shore which is why I am not wearing a life jacket. The pump I am wearing does not talk with the Dexcom CGM).
What if BG drops anyway?
Second, remember to bring low BG treatments with you a especially when you are exercising. Even with a well laid plan, BG can drop, so it’s best to be prepared. I decided to bring Gatorade with me to zumba class as a low BG treatment. Nobody looks at you funny when you are drinking Gatorade while exercising. Chewing candy at the gym takes more effort and you may get some sideways glances when chomping at the gym. With Gatorade, I get the added benefit of hydration that you don't get from candy.
Different bodies react differently to different circumstances, so it is important to experiment for yourself to determine what your game plan will be.
Third, adjust your insulin dose prior to the activity as able. I use an insulin pump so I would set a temporary basal of 50% for 60 minutes prior to the activity (if planned ahead of time) and/or of 0% for the duration of the activity. This can be tricky as this can lead to hyperglycemia a few hours following the activity. You might also have a snack of 15grams of carbohydrate prior to the activity without taking insulin for the snack. Some others might give less insulin at the meal prior to the activity. It’s best not to have too much insulin in your system prior to exercising as this can cause BG to drop very quickly.
Insulin adjustments for exercise vary quite a bit depending on the person and require more foresight into when and for how long you are going to exercise. If you’re like me and like to be spontaneous with your activity (or have kids or a job that put a wrench in your exercise plans), adjusting insulin prior to the exercise is really tricky, so you may resort to having some carbohydrates before the activity to keep BG in a safe zone.
So, here's my game plan for zumba:
Using this plan, I could typically get away with the full hour of aerobic exercise with a 16 oz bottle of Gatorade. Not everyone wants to consume calories while they are exercising but at a certain point in my life, it was either have the calories or don’t exercise. For me, it was well worth it to get in the activity for both my physical and mental health. There were still times that I had to quit after 30 minutes. Even the best laid plans can go awry! Disappointing but I realize that everyone has good and bad days even if they don’t have diabetes so I wouldn’t let myself feel too defeated.
Insulin pump technology for exercise
Here’s where technology can really help make life easier for PWD. I mentioned that having a CGM was really a game changer for allowing me to feel confident enough to exercise. What we haven’t talked about yet is the insulin pump technology that has particular settings for exercising. When the first hybrid closed loop (HCL) tech was on the market, I jumped to get on it. I started with the Medtronic 670G which uses its own CGM to monitor BG and the pump would make adjustments in my insulin delivery to accommodate for the changes in BG. This pump came with “Exercise Mode” in which the target BG during the time frame you choose would change from 120 to 150 mg/dL. Setting Exercise Mode 30 minutes prior to exercise and throughout the exercise made Gatorade practically unnecessary. Of course I still came to the gym prepared to treat a low BG if needed, but I didn’t need to react so much or so often to changes in BG caused by exercising. Hallelujah!! Medtronic is no longer the only HCL system available, and both the Tandem TSlim and Omnipod 5 have an exercise mode setting. Both TSlim and Omnipod 5 work with the Dexcom CGM to make auto adjustments to insulin delivery to allow for safe exercise for PWD. Brilliant!
Different forms of exercise impact BG differently
I realize that different types, intensities and duration of exercise can lead to different patterns in BG. For example, my BG stays pretty steady when I lift weights. Sprinting or short periods of high intensity activity tends to raise my blood sugar. So, when I want to be active but my blood sugar isn’t high enough for biking or dancing, I will try to lift some weights or do anaerobic activities.
My hope for all of us is to spend less time worrying and changing the game plan and more time out there being active and living our lives to the fullest!
As PWD we are constantly experimenting and monitoring the results of each experiment. Different bodies react differently to different circumstances, so it is important to experiment for yourself to determine what your game plan will be. I do not have personal experience with exercise mode on the Tandem pump but I hear from patients that it works really