Type 1 Diabetes – Managing Blood Glucose Levels BEFORE Anaerobic Exercise

Diabetes & Anaerobic Exercise – Paul Coker & Dr Rob Andrews discuss approaches to managing type 1 diabetes before anaerobic exercise.  They talk about what anaerobic exercise is and how high energy explosive exercises like sprinting or weight lifting may have a different impact upon blood glucose levels than exercises that you perform over a long time like gardening, walking or jogging, which are all covered in another video about aerobic exercise.

Introducing Dr Rob Andrews

In this short video Dr Rob Andrews, a world leading clinical expert on diabetes and exercise, shares some incredible insights and guidance on the latest research into Type 1 Diabetes & Aerobic Exercise.  The focus of this video is managing type 1 diabetes before anaerobic exercise.

Paul Coker

Hi. Paul Coker here from 1bloodydrop.com. Today I’m here at the Bristol Royal Infirmary with Dr Rob Andrews. Dr Rob Andrews is a Diabetologist and he has a practise where he specialises in diabetes and exercise amongst other things. Thanks for joining us today Dr Andrews.

Perhaps you could give a quick introduction because I’m sure my introduction has not done you justice. Your knowledge is far superior to the information that I just gave the audience.

Dr Rob Andrews

No, I think you called it exactly correct. I’m just a Diabetologist that takes care of people with diabetes and my interest is giving advice to people who are going for events, marathons or events they’ve never done. Or giving advice to people who are trying to go up the sporting prowess, so elite people, semi elite people or people who are Olympians. To add to that advice, because I’ve always found that the evidence base is not always available in this area, I apply for grants and get money to lead a team in Exeter where we try and answer those questions.

Paul Coker

Fantastic. Excuse me. I know from our previous videos where we were talking about diabetes and aerobic exercise that I learned so much from you in just a few minutes. I’m really excited now to be asking you if I’m doing aerobic exercise and I have Type 1 diabetes, how should I manage my Type 1 diabetes? Perhaps we should start there with what is anaerobic exercise?

What is Anaerobic Exercise?

Dr Rob Andrews

Anaerobic exercise is what we kind of call short and fast exercises. It’s exercises that you’re doing very briefly and you’re trying to get as much power as you can and on the whole is less than a minute. The longest that you can do an event without getting full oxygen, is roughly a 400m run. The best of the best can do that in 40 seconds, but most of us it takes a minute and twenty.

So it’s any exercise that the bit that you do is less than a minute and twenty. That doesn’t mean you can’t do a number of them, but the actual one episode that you do is less than a minute on the whole.

Paul Coker

Typically we are talking about explosive kind of power events. Things like sprinting and perhaps weight lifting.

In our earlier video, we were talking about how you manage your diabetes before you do aerobic exercise, which is a continuous form of exercise. How would strategies for anaerobic exercise differ? What would you suggest to your patients to manage their Type 1 diabetes in anaerobic exercise?

Dr Rob Andrews

Most people who have Type 1 diabetes, when they do an anaerobic event, find that their blood sugars go up during the event. That’s because it’s a short sharp event, you’re doing it high intensity that the body releases hormones to get as much glucose out to flood the system with glucose so it’s available for the activity.

 

The glucose even in people who haven’t got diabetes, goes up, but they quickly produce insulin to pull it down again. That gives you a bit more leeway. Before we were talking about we’re worried that the glucose is going to fall during an event, so we start thinking about what are we going to do with our insulin to reduce the insulin. Do we need to take anything to eat before?

What I tend to say to people when they’re first doing anaerobic exercise is suck it and see. Do the event, measure your blood sugar before and see what happens with it. Then see whether you do need to make any adaptions. If you’re exercising within two hours of the meal, I don’t get people to change their insulin dosages and just say let’s see what happens, because actually sometimes having that excessive amount of insulin around is helpful to stop the blood glucose rising too much.

I  tell them that unless their blood glucose very low and I kind of say if it’s not lower than a 5mmols/l (90mg/dl), that you need to take any carbohydrates. Then just monitor it.

The good thing about doing an anaerobic event, is that it’s a bit easier to do blood sugar measurements, because your doing weights and you’re not doing something continuous, so you can stop and check the first couple of times you do it and see whether it’s falling, whether you need to take anything during exercise. Most times people don’t. So it gives you a bit more leeway and you don’t quite have to have a plan in place, it’s just more monitoring and finding out how it affects you.

Paul Coker

In our video on aerobic exercise, we talked about there being a bandwidth of blood glucose level that you should aim to be at before you start. Is there an equivalent in anaerobic exercise?

Dr Rob Andrews

Yeah. We would normally say if it’s less than 5mmols/l (90mg/dl), then you need to take something. As we said with aerobic, we’re very worried that in that first 10/15 minutes blood glucose is going to fall, so we want you to have a bit of leeway, so we wanted it to be 7mmols/l (130mg/dl). The fact is it’s in anaerobic exercise the blood glucose is likely to go up. If you’re 5mmols/l (90mg/dl) we’re happy for you to start, but just check it’s fine.

Paul Coker

What about an upper limit?

Dr Rob Andrews

The upper limit’s exactly the same. It’s 15mmols/l (270mg/dl). We don’t want you to exercise at 15. Of the two sports, the one we would worry about more you doing, is this (anaerobic) sport, because you don’t have enough insulin around so the glucose might go up. Obviously if you’re doing an event where you’re pouring out loads and loads of glucose, there’s a real risk that it will go up very high.

Paul Coker

If I’ve understood you correctly, the key messages here are to measure your blood glucose level and understand the direction in which your blood glucose level is going before you exercise?

Dr Rob Andrews

Yeah.

Paul Coker

Which is the same for aerobic exercise and to consider taking carbohydrates on board if you’re below 5mmol/l (90mg/dl).

Dr Rob Andrews

Yeah, or the direction of the blood glucose levels is falling falling.

Paul Coker

And to not exercise if your blood glucose level is above 15 mmols/l (270mg/dl)

Dr Rob Andrews

Yeah.

Paul Coker

Thank you very much. That’s really, really useful advice and in our next video we’re going to be talking about how you manage your blood glucose levels during anaerobic exercise. We’ll see you on the next video.