Each time you exercise, you are placinga stress on your body for which anappropriate response is necessary. Thisarticle discusses the body’s response toexercise for the diabetic who is on insulintherapy or insulin secretagogues such asglyburide, glipizide, Glucotrol XL, Amaryl,Prandin or Starlix. It also addresses stepsto prevent diabetes-related complications,hypoglycemia in particular, during exercise. Maintaining safe blood glucose levels duringand after exercise is accomplished througha correct balance of medications, diet andexercise.
Exercise Yields Consistent BGs
For nondiabetics, blood glucose levelsduring exercise remain remarkablyconsistent. This is because the healthypancreas secretes less insulin in response toexercise, which allows blood glucose to bemobilized from the liver and subsequentlytaken up by working muscle to be used asfuel.
The current emphasis on tight blood glucosecontrol to prevent complications associatedwith diabetes increases the potential forhypoglycemia or a fall in blood glucoseduring exercise. In the case of a diabeticwho is treated with insulin therapy or insulinsecretagogues, the failure of blood insulinlevels to decrease with exercise can result inrelatively high levels of insulin and possiblehypoglycemia. For this reason, reducingthe dose of insulin with exercise may helpprevent hypoglycemia. Consult with yourdiabetes care team for strategies in adjustinginsulin dosages to accommodate yourexercise needs.
An Insulin-Like Effect
Another potential contributor to exercise-induced hypoglycemia is the fact thatexercise has an insulin-like effect. Musclecontractions associated with exercisepromote movement of glucose from theblood into the muscle, an action similar tothat of the impact of insulin. In fact, exercisealone can result in glucose uptake intomuscle, independent of insulin. Thus if toomuch insulin is present prior to exercise,hypoglycemia may result. On the other hand,too little insulin present and high bloodglucose or hyperglycemia may be the result.
The American Diabetes Association haspublished a position statement on thetopic of exercise and diabetes. This helpfulresource offers detailed information onthe response to exercise for both type 1and 2 diabetics as well as the impact ofcomplications such as neuropathy andperipheral artery disease on exercise. Thestatement, “Physical Activity/Exercise andDiabetes,” is available from the AmericanDiabetes Association.
1. Avoid physical activity iffasting glucose is greaterthan 250 mg/dl andketosis is present, and usecaution if glucose levelsare greater than 300mg/dl even if no ketosis ispresent.
2. Ingest additionalcarbohydrate if glucoselevels are less than 100mg/dl. Consume extracarbohydrate as neededto avoid hypoglycemia.Carbohydrate foodsshould be readilyavailable during and afterphysical activity.
3. Inject insulin away fromexercising muscles toprevent rapid absorption.
4. Monitor blood glucosebefore, during and afterstrenuous exercise,especially when you arejust beginning an exerciseprogram. Exercise canresult in hypoglycemia asmuch as four hours aftercompletion.