If you have diabetes exercise is one of the best things you can do for your health. According to the experts at Harvard Medical School, it can improve your sensitivity to insulin and help build muscles while shedding excess fat — all of which goes a long way to keeping your blood sugar levels under control.

However, there are certain precautions you should take because of the inherent dangers of the disease. First, always check with your doctor before starting or changing a fitness routine.

“This is especially important if you are overweight or have a history of heart disease, peripheral vascular disease, or diabetic neuropathy,” say the Harvard team of experts. In general, the best time to exercise is one to three hours after eating, when your blood sugar level is likely to be higher. If you use insulin, it’s important to test your blood sugar before exercising.

“If the level before exercise is below 100mg/dl, eating a piece of fruit or having a small snack will boost it and help you avoid hypoglycemia,” the Harvard experts add. “Testing again 30 minutes later will show whether or not your blood sugar level is stable.”

The experts advise that people with diabetes should always wear a medical alert bracelet indicating that you have the disease and take insulin. They also recommend keeping hard candy or glucose tablets with you while exercising in case your blood sugar level drops precariously low.

The American Diabetes Association recommends both aerobic exercise and strength training for those living with diabetes.

“Aerobic exercise helps your body use insulin better,” says the ADA. “It makes your heart and bones strong, relieves stress, improves blood circulation, and reduces your risk of heart disease by lowering blood glucose and blood pressure and improving cholesterol levels.”

The ADA recommends starting slowly and aiming for 30 minutes of moderate to intense aerobic activity at least five days a week. Some examples include brisk walking either outside or on a treadmill, bicycling, dancing, water aerobics, swimming, playing tennis, hiking or roller skating.

Strength training, also known as resistance training, makes your body more sensitive to insulin and can lower blood glucose. It helps maintain and build strong muscles and bones, reducing your risk of osteoporosis and bone fractures. “Also, the more muscles you have, the more calories you burn even when your body is at rest,” says the ADA.

The recommendations include some form of strength training at least twice weekly in addition to aerobic exercise. You can use free weights or weight machines at the gym, use resistance bands, do squats and pushups or take classes that involve strength training. Kick boxing is an excellent way to combine both aerobic movement and strength training. The American Diabetes Association has several suggestions on how to incorporate fitness into your wellness program. Log on to www.diabetes.org/food-and-fitness/.