Exercise Safely

See your doctor for a thorough medical checkup before you start any program of physical activity. He or she should check your:

  • heart
  • blood pressure
  • cholesterol and blood fats
  • body composition, which is your ratio of fat to lean tissue
  • eyes
  • feet
  • glucose levels, including glycated hemoglobin (A1c)
  • other health problems

Your doctor will likely focus on the signs and symptoms of diseases most affected by diabetes. This includes diseases of the heart, blood vessels, eyes, kidneys, and nervous system. Your doctor may also want you to have a graded exercise test, also called a stress test, before you start an exercise program. Stress tests can help you doctor find out if you have any heart problems. They can also be used to figure out how hard you can exert yourself when you exercise.


Your doctor can also refer you to a qualified exercise physiologist who is skilled in working with people who have diabetes. Having your doctor and exercise physiologist work together will ensure that your exercise program is safe and effective.

Take Percautions

Monitor your blood glucose before, during, and after physical activity. Test your blood glucose 30 minutes before your activity and right before starting. If your blood glucose is less than 100 mg/dL, eat something and wait until it's higher before beginning your activity. If itÂ’s a long workout, test every 30 minutes during your activity. Test again after working out. Your test results will help you learn how physical activity impacts your blood glucose levels.

Time your insulin and diabetes pill with your activity level. Physical activity may make your blood glucose drop more than usual after taking insulin. It may also make the insulin work more rapidly. Or an especially hard workout may raise your blood glucose. For best results, talk with your doctor and your physical activity specialist about how to time your diabetes pills or insulin with your meals and with your physical activity. Depending on your physical activity, your doctor may also want to adjust how much insulin you take.

Carry treatment for low blood glucose if you are at risk. Be sure to carry juice, raisins, or another fast-acting sugar source to treat low blood glucose.

Stop if you feel low blood glucose coming on. If you feel faint, clammy, dizzy, or confused, you may be having an insulin reaction called hypoglycemia. Stop working out immediately and have 1/2 cup of orange juice, a nondiet soft drink, or 3 glucose tablets. Don't wait. If you don't treat your insulin reaction, it could get worse.

Wear a medical ID bracelet. Let your teammates or exercise partner know that you have diabetes and how to help in an emergency. If you exercise alone, always wear your medical ID bracelet, and let others know your route, location, and when you'll be returning.

Know when to avoid physical activity. You doctor can help you set specific guidelines. In general, don't work out if:

  • you have type 1 diabetes, your fasting blood glucose is 250 or higher, and you test positive for ketones in your urine
  • you feel ill or have low blood glucose symptoms

Written by Bobbie Hasselbring

Reviewed by Beth Seltzer, MD

Last updated June 2008