Samuel Grossman, BS Pharm, Pharm.D, CDE Answered 1/9/2015

Exercise is more effective when it is being done after meals as opposed to before meals. And it does not matter if you exercise before or after oral blood pressure or oral diabetes-related medications. If you inject premeal or bolus insulin before the meals and you are planning to exercise after the meal, the dose of your insulin may need to be decreased by around 10% or as recommended by your provider. The percent reduction of the dose of insulin depends on the intensity of the exercise and the duration of the exercise. The doses of oral medications that cause release of insulin in the treatment of diabetes such as sulfonylureas as well as other medications used in the treatment of diabetes (such as basal or long acting insulin) may be reduced as well as recommended by your provider if you exercise regularly and your fingersticks are decreased.