Regular activities that make up your day, including eating and exercising, affect your blood sugar. Your blood sugar levels go up after you eat. Another way to say this is that a normal response to eating, specifically eating carbohydrates, is an elevation in blood glucose. A healthy body is able to use that glucose, clearing it from the blood and moving it into the cells for use or storage. Diabetes is a complication involving the inability to properly move glucose from the blood.
Normal Blood Glucose Levels
Postprandial blood glucose values are defined as the values measured at one to two hours after a meal. The recommended blood glucose within one to two hours after eating for a nondiabetic is 140 mg/dL or less. If you have untreated diabetes, your blood glucose may rise to dangerous levels, so you should take steps to keep your blood glucose from going any higher than 180 mg/dL, states the American Diabetes Association.
Complications
Diabetes occurs when your body is unable to move the glucose from your blood and into your cells. This may be due to insulin resistance -- an insensitivity to the effects of insulin -- or insulin production. Insulin insensitivity occurs when cells no longer recognize the hormone insulin, which is responsible for moving glucose from blood and into cells. Another problem may be that the body does not produce insulin. Either way can result in chronic hyperglycemia -- dangerously elevated blood glucose -- which may lead to a myriad of other diseases and conditions, including blindness and loss of extremities and limbs.
Checking Your Blood Glucose
The carbohydrates that you eat should begin affecting your blood glucose within one to two hours after eating. If you are diabetic, this is when you should test your blood glucose. Keep a daily log of your blood glucose levels so that you are sure they are staying consistent. Any dramatic changes or chronic unsafe levels warrant a call to your doctor.
Exercise and Blood Sugar
Blood glucose is one of the main sources of energy metabolism during exercise. To exercise safely and effectively, you must manage your blood glucose before exercise by eating appropriately. Hypoglycemia, or too low of a blood glucose is characterized by a blood glucose of 70 mg/dL or less. Hypoglycemia may occur if you exercise before eating. This circumstance is particularly true for diabetics. Before exercising, eat a small meal two to three hours before exercise or have a snack one hour before exercising. In addition, if you are a diabetic, check your blood glucose before exercise. If it is below 80 mg/dL consume a high-carbohydrate food such as fruit juice and continue to retest until your glucose levels are above 80 mg/dL.
References
- "Cecil Essentials of Medicine"; Thomas Andreoli, Charles Carpenter, Robert Griggs, Joseph Loscalzo, eds.; 2004
- "Anatomy and Physiology"; Kenneth S. Saladin; 2004
- National Diabetes Information Clearinghouse: Diabetes Overview; November 2008
- American Diabetes Association: Checking Your Blood Glucose
- Diabetic Living Online: The Best Time to Check Blood Glucose After a Meal; Virginia Zamudio Lange
- "ACSM's Guidelines for Exercise Testing and Prescription", Mithcell H. Whaley, PhD, et al.; 2006
