Extra carbohydrates for exercise (ExCarbs)
During most exercise (aerobic), muscles use glucose as a fuel and under normal circumstances the body makes more glucose in the liver for this to happen. With insulin use, this cannot occur if insulin levels are high as this stops the liver from being able to do this. The bottom line – carbohydrates need to be taken to balance the amount muscles are using.
One way to manage exercise is to take extra carbohydrate…but how much?
#Rule: Test blood glucose levels every 30 minutes during exercise and review
Easy Approach (based on clinical research)
Assume that muscles use glucose at a rate of 1 g for every kg a person weighs every hour. So for a 70 kg adult they will need to take 70 g of carbohydrate each hour (or 35g every 30 minutes).
Advanced approach (actually very easy as well)
Use tables which are already on the Internet (http://www.diabetesnet.us/node/237).
This method is easy and works for unplanned exercise or if the exercise is more than 2-3 hours after the last insulin injection (so the bolus dose can’t be adjusted) but it may not help if weight loss is the aim.
Estimation of the EXCarbs (in grams every hour) needed to be taken with different types of exercise:
|Activity||Persons weight – 68kg||Persons weight – 90kg|
|Cycling @ 10km/hour||27||34|
|Cycling @ 22km/hour||60||60|
|Running@ 8 km/hour||60||60|
|Running@ 13 km/hour||60||60|
|Walking @5 km/hour||22||29|
|Walking @7 km/hour||45||59|
These are an estimate – you need to factor in your actual weight – the heavier you are the more carbs you need, unless that is you want to use exercise to help lose weight (see Adjusting Insulin for Exercise)
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!