Taking Control of Your Diabetes: Education, Motivation, Self-Advocacy by Steven V. Edelman, MD and Friends
Adjusting for Exercise
If you are lucky, you can fit exercise into your daily schedule on a regular basis at the time most desirable for you. If you are like me and most other people, it is a constant battle to find any time to exercise, let alone a desirable time. My idea of a marathon is a swim in the Jacuzzi, a jog from the couch to the refrigerator, and a bike ride to the ice cream store (just kidding). It is important to know how exercise affects your glucose control. Much of the information will come from preexercise and postexercise home glucose monitoring and a mental diary of how certain types of exercise (including the length and degree of intensity) bring down your blood sugar levels and by how much. There are no short cuts or fancy formulas to predict how you will respond to certain types of exercise. You must test a lot and learn from experience. The best prediction of what will happen to your blood sugar is what has happened in the past during similar types of exercise.
In general, if you know you are going to exercise within 2 to 4 hours of your last dose of Regular insulin (not Humalog or Novolog), you should reduce that premeal dose by 20% to 30%, depending on the intensity and duration of the exercise (Table 10-5). My usual exercise is a 3-mile slow jog (9- to 10-minute mile) and I reduce my premeal fast-acting insulin dose by 25% if I exercise fairly soon after eating. You may not need to reduce your dose as much if you are using Humalog or Novolog since they leave your system much more quickly. In order to avoid problems, it is best to exercise when your Regular or fast-acting insulin is not peaking. If you are one of those exercise freaks who run marathons in your spare time, you obviously need to reduce your long-acting basal insulin as well by 20% to 50%. You may consider becoming a member of the International Diabetes Athletes Association if you want to keep up on the latest information regarding exercise and diabetes (see Appendix 1).
Always test your blood glucose value before and after exercising, and every 1 to 2 hours during prolonged strenuous routines. If it is over 250 mg/dl (13.89 mmol/l), you should consider giving yourself a small amount of Regular or fast-acting insulin, depending on the time of your last dose and how sensitive you are to insulin. If your last dose was within 1 to 2 hours, it might be safer to not take any extra insulin. If your blood sugar level is in the low or normal range (less than 120 mg/dl or 6.67 mmol/l), you should consider taking in some carbohydrates before exercising. Once again, if your last injection was within 1 to 2 hours, it is more likely that your blood sugar levels will get low during exercise than if your last injection was given 5 hours prior to the activity.
One of the "parents' business" items on our current trip to Virginia was a visit by a case nurse from an agency that is trying to get the Out-Laws additional personal and health assistance. While the old folk found her questions intrusive, they were reasonable follow-ons based on the OutLaws' current states of cognitive and physical health. One of the sets of questions was about their medications. A list of them was posted on the door to the den. The case nurse assumed...