There are several strategies for lowering high blood sugar levels. One is exercise. However, be sure to get a blood sugar reading beforehand. If your blood sugar is above 240 mg/dL, check your urine for ketones. If you have ketones, make sure to avoid exercise, since exercising with ketones can actually increase blood sugar levels. You may also want to adjust your diet. Consider working directly with a dietitian to cut out sugar-heavy foods. If diet and exercise aren’t working for you, consult with your doctor about adjusting your diabetes medications.