If you imagine that already having had the injection it is impossible to get that insulin out again so it is going to be working even when you are doing exercise.
If exercise happens EVERY DAY then it is possible to reduce down the basal dose by about 20% to account for this but then if for some reason there is a day when you don’t exercise your sugars are likely to run a bit higher.
If exercise is planned for just a couple of days a week then it is possible to reduce down the long acting insulin the night before but this does potentially leave a risk of the blood sugar going higher later in the day or the next morning.
There are a couple of ways round this:
-to split the lantus or levemir dose so it is taken twice a day so the dose before exercise can be reduced
-to go onto pump therapy if you and your diabetes specialist team are happy with this
-to use a different insulin such a NPH which is a slightly older insulin and doesn’t last as long so can be taken twice a day
Our aim at Excarbs.com is to help people with diabetes using insulin to feel comfortable with taking up exercise – our advice is not aimed at elite athletes but hopefully covers the basic rules for most people living with diabetes.
Remember that if exercise is sustained you will become much more sensitive to the effect of insulin and the dose needed will fall which is a really good result!