Introduction
Managing my blood sugar levels during exercise is a a short documentary style video. It provides a brief insight to help you understand the how exercise affects your blood glucose levels and strategies that might help you to manage your diabetes around exercise. The video was commissioned by Diabetes UK (Cymru) and the Diabetes Research Unit (Cymru) and explores the basics of how to exercise safely with type 1 diabetes. The video follows 4 athletes with type 1 diabetes including Mel Stephenson an international sprinter, Matt Binnie a keen cyclist, Rachael Hunter-Dunn an open water sea swimmer & Paul Coker a half marathon runner. In this video the athletes share the tools, techniques and considerations that they make when they are exercising.
Paul, the founder of 1bloodydrop.com, completed 40 half marathons in his 40th year of living with type 1 diabetes and this video follows him as he completes the final half marathon in this challenge at Swansea on 26 June 2017. Paul says that the most remarkable thing about this run was that he was joined by a team of 29 runners with type 1 diabetes and together they set a world record for the most people with type 1 diabetes to run a half marathon together, many of these runners are also featured in this video. All of the athletes featured here is this video are living with type 1 diabetes and demonstrating that you can exercise safely with type 1 diabetes.
Announcer:
We’re at the start line of the 2017 JCP Swansea Half Marathon. Good luck, guys! Enjoy your journey out there!
Dr. Gilbert:
The big ambition when doing exercise with type 1 diabetes is to keep your glucose levels as normal as possible. That’s down to measuring, record-keeping, hydration; all of which can be helped by some understanding of what’s going on under the bonnet. Despite the challenges, everyone we meet says it’s worth it.
Simon:
Encourage your children to go out and do running and do sport, because actually a healthy, active lifestyle alongside diabetes really helps to control blood sugars as well.
Theresa:
It makes you more sensitive to the insulin, so that you don’t have as many high blood sugars and it’s easier to control.
Gareth:
When I was diagnosed, I was 19; and for two or three years, I just knocked sports on the edge. Yeah, and I’m making up for that time now.
Adam:
Anything can be managed as long as you’ve planned for it and be sensible, you can do anything you want.
Dr. Gilbert:
We’ve met a group of people living with type 1 diabetes, who do sport at a really high level.
Melanie Gray:
I would describe myself, in terms of athletics, as an international level athlete, club athlete, somebody who enjoys it, trains six days a week; so is pretty committed to it.
Rachael Hunter-Dunn:
I just love being out in the ocean. I don’t wear a wet suit. Everyone thinks I’m crazy, but I kind of like that.
Matt Binnie:
I try and aim to go out three times a week, around 80 miles in a week.
Dr. Gilbert:
Understanding what’s happening inside your body when you exercise like this can be helpful.
Paul Coker:
I think that understanding the science is probably the most powerful tool that I have in managing my diabetes.
Matt Binnie:
My level at the beginning of a session will probably be about seven. An hour on, your insulin levels start to go lower than four, maybe three to four.
Dr. Gilbert
When you exercise, your injected insulin allows your body to burn blood glucose as fuel. You may need less of it when you’re actually exercising, but the requirements change before, during, and after; and can be affected by the weather and stress. Many people manage this challenge incredibly well, and as a bonus find that it makes controlling their diabetes easier.
Paul Coker:
In preparation for a half marathon, I’ll actually reduce my background insulin. In fact, I can do it for you now, because we’re about an hour before this half marathon starts.
Matt Binnie:
When I drop my insulin levels at the start of the morning, I’ll notice that my blood sugar levels will obviously be going up because I’m having less insulin. Then, as I leave to cycle, my blood sugar levels will begin to drop. That’s why I’ve knocked back the amount of insulin I’ve been taking, to counteract this. Every hour, I would have some pancakes or carbohydrate gel, just to raise my blood sugar levels a bit. With doing exercise, this will knock my blood sugar levels back down, so then it will result in a steady blood sugar level, meaning I don’t really have to have much insulin at all. At first, it shocked me, but something’s happening in the body that will move the glucose to my cells more effectively.
GLUCOSE TRANSPORTER 4 (GLUT4) is really important in managing my blood glucose level during exercise
Dr. Gilbert:
Enter GLUT4, a protein that occurs in muscle and liver cells, which becomes more active around exercise. If insulin unlocks the door to the cells, then GLUT4 carries the glucose over the threshold. When you’re exercising, the contraction of your muscles will cause GLUT4 transporters to deliver glucose to your cells.
Paul Coker:
The advantage for us with diabetes is that it makes us more sensitive to insulin whilst we’re exercising. That means we need less insulin, so you can then manage your insulin and your diabetes much more effectively.
Rachael Hunter-Dunn:
My blood glucose comes down when I’m swimming, and I know that, so I almost don’t take any insulin at all. I still take on carbohydrate, but it will still balance out; so I actually took my pump off altogether, because I just didn’t want any insulin going in for a certain amount of time. Then, I put it back on half an hour later, having tested my blood glucose again.
Dr. Gilbert:
You can get a waterproof pump, and ideally you’d suspend your pump, rather than take it off. The question is, how do you work out what’s right for you?
Melanie Gray:
Blood glucose checks are really your best friend, in terms of management. How can you expect to know what’s going on with your diabetes without doing checks? You do need to know for optimum performance, whether you’re going for a walk around the park or whether you’re going to the Olympics.
Matt Binnie:
We would just test every ten minutes. When you start cycling or whatever sport you’re doing, you have to do it more thoroughly; but as you get more confident, you can spread out the time, because you know what your levels will be doing. It will be similar every time you go out.
Dr. Gilbert:
After sustained exercise, you’re in a heightened state of sensitivity. Meaning your body is able to use carbohydrate as fuel without your usual amounts of insulin, so you may need to reduce it. And after exercise, your body will also be tucking away any freely available energy supplies or blood glucose to restock the stores in your liver and muscles.
Paul Coker:
The danger with that, for us, is that in the post-exercise period, your blood glucose level can go very, very low, because your body will recover freely available glucose from the circulating blood. That can leave you at risk of a HYPO. Just be very conservative for the amount of insulin that you give after exercise. Your best off to give multiple small doses of insulin, than one big dose; because once you’ve given the insulin, you can’t take it back. As your body is more efficient at using insulin after exercise, you’re at risk of a HYPO, especially in the 8 to 12 hours post-aerobic exercise window. In some people it could take as long as 24 hours, and different types of exercise have a different recovery period.
Matt Binnie:
Once you’ve got that record of what your levels are doing, it’s so much easier. You can just look at it, see where your blood sugar levels are dropping, or your blood sugar levels are rising, and then make the insulin changes accordingly.
Melanie Gray:
I tend to have my meal after I finish training, just because I want to make sure that I’m not in any kind of danger of having HYPOs overnight; because the effects of exercise can last longer than the activity itself.
Dr. Gilbert:
Talk to your diabetes team about strategies to minimise the risk of an overnight HYPO after exercise. It will usually involve reducing your background insulin by around 20%, as well as doses with food; but varies from person to person. Some people find that an insulin pump can make the process easier.
Rachael Hunter-Dunn:
I was using insulin injection pens for many years, and I’ve recently gone on an insulin pump.
Matt Binnie:
A pump is so much more help when you’re doing sport. I would never be able to do what I’m doing now on injections. The pump’s been a miracle. You can do those minute changes, which really help in the long run. It’s just great.
Dr. Gilbert:
Talk to your dietician if you’re thinking about carb loading for endurance events. That’s building up stores of glycogen or fuel in your muscles and liver.
Paul Coker:
Carb loading has a cumulative effect. It’s not just having the pasta party the night before, as many marathon runners think.
Rachael H. Dunn:
In advance of my 8K swim, I took on enough carbohydrates the day before to be ready for some slow release of energy.
Paul Coker:
In my opinion, carb loading is extremely important, and it also increases the speed at which you recover from exercise.
Dr. Gilbert:
However, take advice first. There is some evidence that it can damage your long-term glucose control, as measured by your HbA1c, so do discuss it with your diabetes team. Don’t forget about variables like the weather. Heat opens up blood vessels, increasing the absorption rate of insulin; while cold does the opposite.
Melanie Gray:
If it’s a particularly warm day, I know that the uptake of my insulin is a lot quicker.
Dr. Gilbert:
Dehydration can raise blood glucose levels and cause temporary resistance to insulin.
Melanie Gray:
If I’m well hydrated, I don’t see so many highs.
Dr. Gilbert:
Perhaps an interesting way to look at the effect of exercise is to see what happens when you stop, as Mel found out when she injured her achilles tendon.
Melanie Gray:
What I found is that my background insulin, which is the equivalent of basal insulin on injections, I had to increase by nearly 30%. I found that previously, when I was training, my carb to insulin ratio was for every 10g of carbohydrates I would eat, I’d need one unit of insulin. Whereas as now, I need one unit of insulin for every 8g.
Dr. Gilbert:
There’s always more to say than we can squeeze into a short film, but there’s good information online about specific types of exercise. Do explore these links to find out more; and we’ll give Mandy, one of the runners at the Swansea Half, the last word.
Mandy:
Please don’t hesitate. Make sure you’re exercising, at any level. There’s nothing that can stop you with type 1.
With special thanks to Diabetes UK (Cymru) for allowing 1bloodydrop to participate and share this short film. For more information about Pocket Medic and its films, contact info@pocketmedic.org