# Worried about blood sugar control when exercising



## Polyphenia (Sep 27, 2010)

Hi I have type 1 diabetes and was diagnosed 32 years ago. I need to lose about a stone and a half. Dieting alone won't work so I want to exercise more.

The problem I have is that whenever I have tried exercise in the past my blood sugars tend to drop dramatically low some hours later. So I end up taking some sugar and eating something which puts me back at square one. Should I lower my insulin dose or just try less strenuous exercise. At the moment my only exercise is to walk the dog in the evening.

Thanks for any advice.


----------



## Caroline (Sep 27, 2010)

Not certain on this, but I think you may need to eat a small ammount of carbohydrate before you start.

I moved this to the exercise message board as a more apporpriat place.


----------



## Northerner (Sep 27, 2010)

Hi Polyphenia, welcome to the forum  It's common for blood sugar levels to fall in the hours after exercise - for me the effects can last for up to 40 hours! You will need to experiment to find out the best approach to dealing with this. It may be that you need to take less insulin prior to exercise and also for the meals following i.e. reduce your ratios of insulin to carbs. If you are on injections, you may also need to consider reducing your basal insulin if the exercise programme is stepped up over a period of days. If you are pumping, then you may need to reduce or even stop your basal insulin during and fr a period afterwards.

In my case, I find that I need the normal amount of insulin for my meal prior to exercise, but then need to reduce post exercise meal insulin by about 25%. As I am currently training for the Great South Run I have found that the extended periods of exercise has resulted in me reducing my lantus (basal) by 50%!

Some people find that 'topping up' with some carbs after exercise helps prevent drops later on. When you exercise, your body uses the energy stored in your muscles, followed by energy stored in your liver. After exercise, the muscles and liver seek to replenish their stores and take the sugar from your blood, resulting in your levels dropping low. It's a very personal thing, but the best advice is to experiment in a safe environment e.g. at home or in a gym with easy access to fast sugar - jelly babies or lucozade etc. Test frequently to find out what is happening and treat if necessary. As you get fitter, your body is better able to cope with a certain level of exercise. For example, I can run around 5 miles without extra sugar, but need about 10g sugar (2 jelly babies) for each mile afterwards.

Don't worry about having to have snacks and how this might upset your attempts to lose weight - the effects of the exercise will far outweigh (so to speak!) the extra carbs, so long as you don't go mad and eat a whole box of jelly babies! 

Let us know if we can be of more help


----------



## Polyphenia (Sep 28, 2010)

Hi Northerner, thanks for all your advice. I have to admit to enjoying the odd jelly baby! I'll take it step by step, I suspect I will need to lower my insulin dose after exercise.

I am planning on exercising after work and before my evening meal.


----------



## Robster65 (Sep 28, 2010)

Hi Polyphenia. 

It's the same problem we all face unfortunately. You exercise to lose weight and end up eating a pile of sugar and gain weight. 

I found it easier to think of it in terms of exercise increasing insulin sensitivity, so if you can do a set amount of aerobic at pretty much the same time each day (eg. a strenuous walk), you should be able to predict how much extra carbs you need and then translate that into a drop of either bolus for the next couple of meals and/or a drop in basal to cover the longer term effects.

I managed, with a lot of help form my partner, to cut down on calories too without losing too much from my plate. We got down to about 1800 or so calories.

Rob


----------



## Polyphenia (Sep 29, 2010)

Thanks Robster, I have 3 meals a day and no snacks. The only meal I could really cut back on is my evening meal but still every little helps.

Thanks for your advice.


----------



## Northerner (Sep 29, 2010)

I would recommend getting hold of a copy of the Diabetic Athlete's Handbook by Sheri Colberg - very useful for understanding how insulin works in the body and also the physiology of exercise.


----------



## Polyphenia (Sep 29, 2010)

Thanks Northerner that book looks very helpful. Even after 32 years of diabetes there still things to learn. Much appreciated.


----------



## Northerner (Sep 29, 2010)

Polyphenia said:


> Thanks Northerner that book looks very helpful. Even after 32 years of diabetes there still things to learn. Much appreciated.



I was due to run a marathon the wek after I was diagnosed. I didn't make it, but was determined to get back into my running as soon as I could, and this book really helped - I managed to run the Great South run just four months later.  It's in 'American' so you have to divide all the BG numbers by 18 to understand them properly, but apart from that it's very good!


----------



## Copepod (Oct 2, 2010)

*www.runsweet.com*

www.runsweet.com is a good free resource website for UK based people with diabetes who use insulin and participate in any sports, not just running and athletics. Lots of information about physiology, specific activities etc.


----------



## lingy16 (Oct 7, 2010)

i have the same problem, i seem to find that sometimes i can do a couple of hours at the gym, and then up having to eating jelly babies etc when done to restore my level! I try to have something carby before, like a apple/bannana so im a littel higher when i start excerising! so that i dont have to worry! i do find though i generally need less insulin on my next meal other wise i can go hypo in the night! sometimes it just sucks having to plan everthing!!


----------

