Planning Insulin Around Activity
Reviewed by CDE Mehandi Sharma · Updated
The two levers around exercise are insulin and carbohydrate. Which one you use, and how much, is a decision to make with your care team rather than from an article.
The standard advice is explicit about this: check your blood glucose before, during and after activity, and ask your doctor whether you should take less insulin or eat carbohydrate before, during or after being active.
The reason it must be individual is that the answer depends on your insulin, your doses, the timing of your last meal, and what kind of activity you are doing.
What you can do generally is build a picture. Check before you start. If you are near the low end of your range, that is a reason to eat something first rather than to begin and hope. Check afterwards, and again a few hours later, because the delayed drop is the one people miss.
Write these down alongside the activity. After two or three repeats of the same exercise you will have a usable pattern — and that pattern is what turns a vague conversation with your doctor into a specific adjustment.
Always carry fast-acting glucose. And if you exercise in the evening, pay particular attention to what happens overnight.