Building Competency in Diabetes Education THE ESSENTIALS

BASAL-BOLUS INSULIN THERAPY | 12-102

recommended to fuel performance (166). Generally, insulin is not taken for carbohydrate consumed during activity. Patients should take into account the insulin action and should consider time since last rapid- insulin injection. Blood glucose levels should be measured at regular intervals to ensure BG levels are safely maintained. Checking blood glucose in the post-event period, every one to two hours, is important to assess response to activity and food consumption and to avoid post- activity hypoglycemia. Insulin adjustment Several factors should be considered when adjusting insulin doses for exercise (164,167): 1. Insulin action and the time span between the onset of exercise and the previous insulin injection: If exercise is performed when circulating insulin levels are lower (more than two hours following the last injection of rapid-acting insulin or three to four hours following the last injection of short-acting insulin), minimal or no insulin dose adjustment may be required. 2. The longer the activity and the more physically trained the person is, the more dramatic the insulin dose adjustment should be. 3. Insulin doses for meals following exercise may need to be reduced due to post-exercise increases in insulin sensitivity. This is especially true for activity performed in the evening. General guidelines • When activity follows a meal, begin with an insulin dose reduction of 20 to 50% for moderate activity and 50% for strenuous activity. Prolonged exercise ( ~ three hours or more) may require a reduction of up to 80% (164,168). • Blood glucose readings before, after and even during exercise should be used to determine appropriate change in insulin or food the next time activity is done. It is important for the person to know the action of their insulin so that adjustments are made to the appropriate insulin dose (164,168). • Morning and afternoon activities may require reduction of the morning basal insulin by 30 to 50%. Trained athletes may require up to 80% reduction for long-duration activities. For those using CSII, basal insulin should be significantly reduced, or suspended (only if the activity is ≤ 45 minutes), for the exercise duration. Start with a basal reduction of 50%, 90