Prolonged physical activity - Anybody run a marathon?

[diabetest2]

I'm doing a 10k several times a week but don't really know how it affect my sugar levels. I'm Type 2 and try to run a marathon. It's hard training knowing that prolonged running is probably causing drops or spikes of my blood sugar.

I want to run a marathon and train 21k and so on, but I'm afraid of the downs or ups. Does glucose vary that much with prolonged physical activity?

 

[Julian_Hands]

Hi, I don't do marathons but do Audax cycling with extended rides over 200km.
Endurance exercises like this require careful control but once mastered can be superb.
You can't just eat before you start and hope to burn it off as this will end in injury due to you blood not being able to get the glucose into your muscles.
I Reduce my long acting basal insulin by a 1/5th the night before then reduce my bolus fast acting insulin by 50% with breakfast. I keep my blood glucose around 5-7 mmol/l by eating flapjacks and take energy gels, dextrose and jelly babies with me, just in case I start dropping fast. If I'm below 5mmol/l I'll take 6 dextrose tablets or 6 jelly babies plus eat some flapjack, the dextrose gives the boost and the flapjack gives endurance carbs that will last about 45 minutes.
You need to balance your carbs with your bolus fast acting insulin as you can't not have any. You need insulin to process the glucagon you eat, just reduce else your have hypos.
Good luck and don't let it beat you, it takes a bit of work but very rewarding once you've cracked it.

 

[catapillar]

Have you tried doing a run and actually testing to find out what your blood sugar is doing, rather than just guessing? Testing probably more effective than guessing.

 

[Bill166]

Agree with both previous replies, it's more difficult to do serious exercise with diabetes , but it's very possible . I'm not a runner, but I do a lot of cycling and like Julian I've found the best technique is to a) lower insulin levels b) carry both high and low GI foods to keep bg levels up c) test a lot, especially when ramping up distances or effort - everyone is different , you have to find the amount of drugs and food that works for you in different circumstances. One surprising thing I've discovered is that I should never eat glucose before going up hills! When you seriously work muscles they produce stress hormones, prompting the liver to release glucose from storage, I usually end up with a higher bg at the top of a hill than when I started. . .

 

[Brunneria]

Hi and welcome,

I think it might help people if you gave a bit more info, to assist in their answers.

For instance,
- what medication are you on? If any? Everyone who has answered so far is on injected insulin, so they have to take that into account, but if you aren't, then your testing/training will not have to consider that, and you are far less likely to hypo.
- have you got a blood glucose meter (many, many T2s are told not to test, and don't have meters, so you may not have any way to gauge your blood glucose at the moment, although you CAN buy one and use it)
- What are you eating before, during and after your runs? Do you eat carbs before or after training? or do you eat low carb? That sort of thing.

Hope that helps.

 

[diabetest2]

Julian, that was some detailed info, thanks a lot!

I try to balance my diabetes with healthy diet and exercise; trying to avoid medications as much as possible. I think it was a good suggestion to bring my meter and test strips with me on the run and figure out for myself how it affects me personally.

Testing a lot is the way to go. I just hoped it would be in some way predictable how the glucose will react. Don't want to spike or fall of the cliff if I exercise too much.

Would you suggest a regular glucose meter or should I use CGM? There a big difference in cost.

 

[catapillar]

You say you are avoiding medication? Is that successfull? How are you treating your diabetes? If you aren't taking medication that can cause hypos, then self funding a CGM might be rather a large leap before the step of actually using the glucose monitor that you do have when running

You may well find that the impact running has on your blood sugar is predictable. But you need the raw data of the test before you start trying to predict. I can have a good guess what a run is going to do to my blood sugar. But I'm not you.

Just take your metres out on a run. It wants to get out in the great outdoors

 

[KarenG]

Hi,

I'm T1 for 40 years so not sure how helpful my comments will be but here goes:

For long runs I've found the Freestyle Libre the most wonderful tool. I always found stopping, with shaking hands, getting out strips (trying not to drop them!) and testing a bit of a pain, albeit essential. The Libre has been like a miracle for me. I reduce my basal for long runs. Always always carry Jelly Babies or similar. Also cash, mobile phone "just in case" (sensible precaution for long runs anyway). On occasion my blood sugar goes sky high, usually in a race, and that is the absolute pits and I take a correction dose.

I try and always have food with lowish GI before going out, but that I know my stomach can cope with.

I was able to train for, and successfully complete the Dopey Challenge in Jan 2015. This consists of four races on subsequent days: 5k, 10k, Half Marathon and Marathon. Anything is possible if you want to do it I'm doing it again this Jan coming.

 

[Bebo321]

Julian, that was some detailed info, thanks a lot!

I try to balance my diabetes with healthy diet and exercise; trying to avoid medications as much as possible. I think it was a good suggestion to bring my meter and test strips with me on the run and figure out for myself how it affects me personally.

Testing a lot is the way to go. I just hoped it would be in some way predictable how the glucose will react. Don't want to spike or fall of the cliff if I exercise too much.

Would you suggest a regular glucose meter or should I use CGM? There a big difference in cost.

There is little point in funding cgm unless you are using insulin. If you are able to manage your BGs with diet and exercise alone, there is nothing to stop you upping your distances significantly. All that will happen is that you will improve your insulin sensitivity even further. Well worth taking a test kit out with you when you run a few times just to see how your body reacts, but beyond that you're hopefully in that fortunate position where you can run as far and as often as you like without having to worry about low bloods. Yay!

@Julian_Hands , I'm not sure if you know, but you don't actually need to take any insulin to balance the carbs when you're exercising. When you exercise your GLUT4 transporters (they enable the uptake of glucose into your working muscles) proliferate in number and mobilise to the surface of your cells. Bottom line is, you don't need any insulin to get the energy into your muscles - your body has a way of doing it for you. Just thought it might help in case you're trying to juggle fuelling with insulin dosing.

 

[Snapsy]

I was able to train for, and successfully complete the Dopey Challenge in Jan 2015. This consists of four races on subsequent days: 5k, 10k, Half Marathon and Marathon. Anything is possible if you want to do it I'm doing it again this Jan coming.

Wow! Sounds incredible!