If you struggle with exercise, join the club! Dr. E and Dr. P have been living with type 1 since they were 15-years-old, and even as endocrinologists, it’s a challenge for them to stay in range when they work out. However, they have some great tips on what you can do to try to avoid exercise-related lows and post-exercise rebound highs.
A Recap of Our Tips on Exercising with Diabetes for Type 1s, and Type 2s on Insulin
1. Plan Ahead!
- The time of day you exercise is important! People tend to be more insulin resistant in the morning and more insulin sensitive at night, which means it’s harder to go low in the morning and easier to go low at night. If you’re dealing with lows, consider adjusting the time of day that you exercise – if you can.
- Try to prepare 1-2 hours before working out. If you’re on a pump and you’re adjusting your settings for exercise, you really should do it an hour or two beforehand.
- If you are on injections, you may need to snack a little to get your glucose level higher than normal so that the workout brings it back down without a low.
- In terms of order of exercise, doing weights or strength training before your cardio has been shown to reduce lows with that cardio activity.
2. Adjust Your Pump Settings
Note: We don’t recommend taking your pump off during exercise. Doing so will make your body insulinopnic (low levels of insulin). As a result, when you stop working out, you create a perfect storm for rebounding high. This is because your insulin levels are very low but your stress hormones (adrenaline, glucagon, and others) are still at a high level.
- If you’re on a hybrid closed-loop pump, you can put your pump in exercise mode, or if you’re on a regular pump you can create another program for reducing the basal rate i. Remember you have to kick the settings in an hour or two before exercise (and remember to take them out of exercise mode when you’re done working out or even a little earlier as you are finishing your exercise to prevent rebound).
- Example of DIY Loop Settings from Steve: Steve is on a DIY loop system, and an hour before working out he changes his usual goal from 120 to 160. He reduces his basal insulin delivery from 100% to 80%, and then he puts in a time duration for his exercise settings so he doesn’t forget to turn them off. His blood sugar goal going into a workout is 150-160 with a horizontal trend arrow.
3. If You’re on MDI
- If you’re on MDI, try to go into exercise a little on the high side. Jeremy’s pre-exercise goal is between 180-200. You can accomplish this by either snacking before you work out, or intentionally under-bolsuing for your most recent meal before you work out.
4. Make Adjustments During Your Workout If Necessary
- You may need to make some pump adjustments during exercise. For example, if Steve is running higher than he would like during his workout, he reverts back to his usual pump settings that do NOT have any insulin dose reductions.
- If you’re on MDI and you need to take an insulin injection during your workout, you can inject with your pen through clothes if you need to, as Jeremy always like to show off.
5. Avoid the Post-Workout Rebound High
- Take a couple of units of insulin 10-20 minutes before you finish your workout to help get some insulin on board.
- A cool down is critical! If you’re on a stationary bike, slow your pace and lower your incline for the last 10 minutes, or if you’re out for a run, walk the last mile home. Don’t go full throttle for your workout and then just stop.
- If you do have a rebound high (sometimes we call them “hollow highs” because it’s the adrenaline kicking in) and you need to correct, try giving yourself half as much insulin as you normally would.
6. Don’t Forget!
- After your workout, change your pump settings back to normal if you haven’t already.
- Remember you can be insulin-sensitive for the next 12-24 hours after exercising, so look out for potential overnight lows, especially if you exercise in the evening. You might need to back off on your insulin if you’re on a pump to avoid that if you notice that happening.