Moderate to vigorous exercise can help you maintain normal blood sugar, or glucose, levels or lower blood glucose levels if you are or have been recently diagnosed as diabetic. Exercise can sometimes make your blood sugar drop too low, resulting in a condition known as hypoglycemia, or low blood glucose. Diabetics, who usually take glucose-lowering medications, must be especially careful and check their glucose before, during and after exercise to prevent hypoglycemia.
Normal Range
According to the American Diabetes Association, the normal pre-meal, or fasting, blood glucose level in a healthy adult ranges between 70 milligrams per deciliter, or mg/dL, and 130 mg/dL. The normal post-meal blood glucose level is between 130 mg/dL and 180 mg/dL. A reading below 70 mg/dL is too low. Exercising with low blood sugar may leave you feeling too weak to perform at your peak. Diabetics should check their glucose before working out. If you get a reading of 70 mg/dL or lower, eat some hard candy or drink some juice before you work out.
During Exercise
You should be able to exercise with no problem if your blood glucose ranges between 100 mg/dL and 250 mg/dL, according to the Mayo Clinic. You should test your glucose again 30 minutes into your workout to make sure it has not dropped too low. If you're working out longer than an hour, check your blood sugar every 30 minutes.
After Exercise
Normal blood sugar after exercise should be around 100 mg/dL, according to the Joslin Diabetes Center. If your post-workout blood sugar level falls below 100 mg/dL, eat a few pieces of hard candy or drink some regular soda or fruit juice to boost your sugar levels. Check your blood sugar again before you go to bed. If it is still too low, have another small carbohydrate snack. Check with your doctor to see if you can double your medication at bedtime if your blood sugar levels remain low after exercising.
Caution
Stop working out immediately if your blood sugar falls below 70 mg/dL during your workout. Have some juice or candy and then test your blood sugar again in 15 minutes. If it has not risen above 70 mg/dL, have another carbohydrate snack. Keep checking your blood sugar every 15 minutes and eating a carbohydrate accordingly until your blood sugar is at a normal range before resuming exercising.
References
- American Diabetes Association: Living With Diabetes: Checking Your Blood Glucose
- Mayo Clinic: Diabetes and Exercise: When to Monitor Your Blood Sugar
- Joslin Diabetes Center: Why Is My Blood Glucose Sometimes Low after Physical Activity?
- National Diabetes Information Clearinghouse (NDIC): Hypoglycemia
