- About 30 minutes after the exercise has ended, the child's blood sugar will be checked. If it is less than 250 mg/dL, a snack will be given and the last blood draw for the study will be made 15 minutes later. If the blood sugar is 250 mg/dL or higher, no snack will be given and the child's blood sugar will be checked in 15 minutes. At that time the child's insulin pump will be started if it was stopped, and a correction dose of insulin may be given.