Mar 09 2009
Blood Glucose Levels
Knowing when your blood glucose level is likely to fall will help you identify what – if any – action you need to take. If you are starting physical activity for the first time, test your blood glucose and check the effect that daily physical activities such as shopping and gardening have. If you already do some regular activity, note what effect that has and then compare the effect of more vigorous activity.
If you take tablets or insulin, check your blood glucose level before and after your activity, and again a few hours later. If you are active for more than an hour, it is a good idea to check your blood glucose level in the middle of the activity. If you don’t take tablets or insulin, you won’t need to make any changes whether although testing your blood glucose might be useful to see what a positive difference physical activity can make.
The following measures will help you keep your blood glucose controlled if necessary:
If you have high blood glucose levels before you exercise, and it does not fall as you expect or rises even further, you probably don’t have enough insulin to help your muscles use the extra glucose your body is producing. You may need to increase your tablets or insulin dosage to ensure that your blood glucose is well controlled before you exercise.
If you have Type 1 diabetes and your blood glucose level is over 15 millimoles, avoid exercise until your blood glucose is lower. When you have a high blood glucose level like this, physical activity may cause it to rise even higher and in this situation ketones may be produced and ketoacidosis may result. Taking your insulin and wailing until it has had an effect will rectify this situation.
If you know that your activity will give you a low blood glucose level, you could reduce your dosage of tablets or insulin beforehand.
If your activity is unplanned, or you know it won’t make a big difference to your blood glucose level, you might have an extra snack beforehand rather than adjust your tablets or insulin.
If you have a low blood glucose level before your activity starts, you will need to eat something – ideally half an hour before the activity
If your blood glucose level is still falling a few hours after activity, you will need to eat something then.
If you are intensely active for more than an hour, you will need a top up of glucose during the activity – energy drinks or sports bars will give your muscles the extra glucose they need. Energy drinks, every 1-1 1/2 hours will ensure that your body’s glucose levels do not fall too low.