I am a fairly active 34-year-old female. In the past five months, I have started running three miles a day outdoors. I power walked for many years before that and always had to cut my bolus down due to hypoglycemia for up to 24 hours afterwards. Since I started running, I have been subtracting two units from my breakfast dose and then exercising within 30 minutes of eating. My blood glucose usually runs on the higher side after running and sometimes increases even more after I eat lunch. Wouldn’t an intense short run cause low blood glucose more than a power walk? If not, am I still getting the benefit of running three miles every day as I would like to lose 15 pounds? I just would assume that running would require me to cut my bolus, which would help me to lose weight more quickly.

Great question! I would need to ask more questions to get a clear picture, but, hopefully, the information here will help give you the answers for which you are looking.

Both running and walking will lower your insulin requirements, which will help you lose weight. The important differences between the two are how hard the activity is for you (the intensity) and how long you are active for (the duration).

An intense, short workout is different from a medium-intensity, longer workout, even though you could burn 200 calories with both. Intense workouts require more energy (sugar stored in the muscles of your body) initially, but, after, can actually keep your metabolism in a higher state for a longer amount for time (meaning you may burn calories after the workout, too!) So, the question would be how hard is the running for you? You may, in fact, be lowering the right amount of insulin (and that is something to ask your healthcare provider for advice on), but it may not be at the right time.

With that being said, something you may want to ask your healthcare provider about is lowering your basal rate for exercise. Many people will lower their rate before a workout and, depending on the intensity or the duration, keep their basal rate at a lower level after their workout. Many will also do a combination of basal/bolus lowering to get the effect they want.

One other tidbit to consider is eating a large meal before exercising. When exercising, the body moves the blood away from digestion to the muscles. So, you prolong digestion when you eat a large meal before working out. There’s nothing wrong with that, but don’t expect to digest the meal as if you have not run.

As you can already see, this is a tough one to answer, but I’ve got faith in that after talking to your healthcare provider, you can get it right. Good luck!

BF