Amanda Wilde (Host): For people with type 1 diabetes, exercise can make a profound difference, but it can be difficult, so we're focusing on adjusting management of type 1 diabetes with exercise with Dr. Joe Henske, Director of the Diabetes Program at UAMS Health. Dr. Henske was diagnosed with type 1 diabetes himself at the age of 15 and has committed his life to helping others with diabetes better manage their disease and live life to the fullest.

Thank you, Dr. Henske. This is UAMS Health Talk, a podcast from the University of Arkansas for Medical Sciences. I'm Amanda Wilde. And welcome, Dr. Henske. Great to have you.

Dr. Joseph Henske: It's great to be here, Amanda.

Host: Well, let's start with exercise. How do you exercise effectively and safely if you have type 1 diabetes?

Dr. Joseph Henske: I think what we want to do when we have diabetes or type 1 diabetes like I do and like so many other people do is to live a normal life and do the things that you like to do, like exercise. Exercise is so important for our life, cardiovascular health, for our mood, for our strength and muscles to move around. And so, I think the key is how do we do that? How do we manage taking insulin, taking in food and things like this and maintain our blood sugars in a safe range? And I think that's kind of what we're thinking about today.

Host: So, how does exercise affect the blood sugars in people with type 1 diabetes?

Dr. Joseph Henske: Well, the physiology of exercise is very complex. Normally, the body adjusts insulin levels to accommodate exercise, knowing that when you exercise, you're using up a lot of glucose. Your muscles are using that glucose for energy to help you run and jump and swim and bike. And your body, if you don't have diabetes, makes less insulin, so that your blood sugars don't drop too much. Insulin is a hormone that can lower your blood glucose levels. Now, if you have diabetes or if you have type 1 diabetes and you're taking insulin, you need to make those adjustments and adjust how much insulin you give yourself during exercise, because your body can't do it naturally because all the insulin that's in your system with type 1 diabetes is insulin that you've given to yourself.

Host: So, these are strategies people with type 1 diabetes really need to consider when getting into exercise. How should blood sugar levels be monitored then before, during, and after exercise so that we know where we're at?

Dr. Joseph Henske: It's always a good idea to know what your blood sugar levels are and where they're headed. I think the easiest way to do that and the most effective way to do that is to wear what's called a CGM or a continuous glucose monitor. This is a device that you can wear typically on your arm or your abdomen, which will read your glucose readings. You can also stick your finger the traditional way and draw a blood sample to see what your blood sugars are. But by knowing what your blood glucose levels are, heading into exercise, during exercise, and after exercise, that's going to help you maintain levels as close to normal as possible during exercise.

Host: And then, does regular physical activity aside from exercise affect insulin requirements?

Dr. Joseph Henske: Absolutely. That's a great consideration, is what is considered exercise? If I'm mowing the lawn, if I'm vacuuming the house, if I'm tidying things up, is that physical activity going to drop my blood sugar levels? Yes. Any physical activity over and above rest is really a form of exercise.

Now, if you go out and run five miles, or you go out and run a marathon, certainly that's going to be a greater requirement to make adjustments to your insulin levels and also to take in carbohydrates for exercise. Those are really the two things that you have as sort of your main controls to keep your blood sugars in range during exercise, it's to reduce your insulin levels, and to take in carbohydrates or sugars or food.

Host: You were just referring to, you know, marathons and intensive exercise. So, you've run 15 marathons. Have you noticed anything in your training, that informs what we're talking about today, exercise and diabetes?

Dr. Joseph Henske: Yeah, absolutely. That's one of the main reasons I love talking about type 1 diabetes and exercise and running marathons is because I do it myself. And I just ran the Chicago marathon about a month ago, and it requires a great deal of preparation and understanding in order to know how to maintain your blood sugars in a good range over three, four, five hours in some cases when people run marathons. And so, I think that it requires practice, doing the same thing over and over and seeing how your body responds, what level of insulin adjustments are required, how many carbohydrates you need to consume during exercise. I usually cut my insulin doses in about half when I'm exercising or running a marathon. I use an insulin pump, which I can make adjustments with that. And I take in about 40 to 60 grams of carbohydrates per hour of exercise. And that's usually in the form of a carbohydrate gel. You can buy sort of a prepackaged gel, but you could also eat candies, jelly beans, things like that that have fast-acting carbohydrates or sugar sources. Some people drink a sports drink like a Gatorade, and you can also consider that part of your carbohydrate intake during exercise to keep your blood sugar levels from dropping too low.

Host: And timing of food is always something you're thinking about when you have diabetes. Does the timing of exercise throughout the day or the frequency of exercise in a week play a role in any of this?

Dr. Joseph Henske: Yeah. Timing is really important. Timing of when you have your meal in relation to your exercise is also really important because it impacts how much insulin is in your system. if you exercise shortly after a meal, you've probably taken a considerable amount of insulin for the food that you've eaten. And that insulin then is going to be active during the time period that you're exercising and is going to put you at risk of having a low blood sugar level during exercise. So oftentimes, exercising, when you haven't eaten in a while can actually be a useful strategy. Timing of exercise during the day can also be important.

It's important to know that when you exercise in the morning, you are more insulin resistant. And so, you might not require as much insulin adjustment in the morning. You might not require taking in as many carbohydrates in the morning. And so, those are some factors. If you exercise in the evening, you might be more likely to have low blood sugars overnight as well. And so, if you're concerned about low blood sugars with exercise, sometimes exercising in the morning on an empty stomach with very little insulin in your system can be very useful to avoid low blood sugars.

Host: Well, along that line, do you have other nutrition tips and/or hydration strategies that are best for people with type 1 diabetes?

Dr. Joseph Henske: I think when you have type 1 diabetes, you want to eat a balanced healthy diet. It's got to have carbohydrates, but also proteins and fats. And I don't think the nutritional recommendations for someone with type 1 diabetes are any different than the general population. Your goal is to maintain a healthy weight and get good nutrition and physical activity.

When you are exercising, it's very important though to carry a carbohydrate source with you at all times. And so, you should have a little pouch or some pockets that you can carry additional carbohydrates because you're going to need to take in carbohydrates if you're exercising for more than probably 30 minutes at a time so that you don't face the risk of a low blood sugar.

In terms of drinking fluids, again, sometimes you can use that fluid like a Gatorade or a sports drink as a carbohydrate source. But of course, it's also important to maintain hydration with water and your body really needs water during exercise to avoid dehydration, particularly in the summer months and things like that.

Host: Dr. Henske, thank you for these recommendations and explanation of what works for exercise with type 1 diabetes and ways to be safely proactive with exercise and health.

Dr. Joseph Henske: You're welcome. Thank you.

Host: Dr. Joe Henske is the Director of the Diabetes Program at UAMS Health. To make an appointment at UAMS, call 501-686-8000. If you found this podcast helpful, please share it on your social channels and check out the entire podcast library for other topics of interest. This is UAMS Health Talk, a podcast from the University of Arkansas for Medical Sciences. Thanks for listening.