Insulin and Medication Adjustments for Post-meal Activity

When physical activity takes place within 2 hours after a meal, cutting back on insulin or medication should be sufficient for preventing hypoglycemia.  It also has the added benefit of promoting fat metabolism and weight loss.

 

For those who take mealtime insulin, the total dose – including the meal dose and the correction dose – should be reduced by a percentage.  The higher the workout intensity and longer the anticipated workout, the greater the reduction.  For example, someone who normally needs 6 units of rapid insulin for a meal should reduce the dose by one third -- to 4 units -- prior to a moderate-intensity 45 minute workout.  

 

For those taking a meglitinide prior to the meal, if the premeal blood sugar is near normal, the medication may be skipped entirely.  Likewise, a longer-acting sulfonylurea dose may be reduced or omitted if the blood sugar is near normal and exercise is planned.

 

•Low Intensity:                             ê insulin bolus 25% •Mod. Intensity:         ê insulin bolus 33% •High Intensity:         ê insulin bolus 50% •Skip meglitinide •Skip or reduce sulfonylurea

 Of course, these adjustments should be made with consent of the patient’s prescribing healthcare professional.  A review of blood sugar and workout records will allow fine-tuning of these adjustments in order to achieve optimal glycemic control.

 

Snacking to Prevent Hypoglycemia for Pre- or Between-Meal Activity

For exercise that takes place before or between meals, those at risk of hypoglycemia should be advised to check their blood glucose level and consume an appropriate amount of carbohydrate.  The chart below shows the approximate amount of glucose burned during 60 minutes of exercise at varying intensities.  Consuming this amount of carbohydrate prior to activity should keep the blood glucose fairly stable.  For shorter bouts of activity, less carbohydrate is needed.  A half-hour exercise session will require half of the amount listed.  For longer bouts, consuming carbohydrate at hourly intervals is best.

 

Of course, if the pre-exercise blood sugar is above target, less carbohydrate will be needed.  If the blood sugar is below target, additional carbohydrate will be needed before starting an exercise session.