Having diabetes or being prone to fluctuations in blood sugar levels means constantly monitoring meals and tracking how they affect your blood sugar level. Adding to this, exercise can cause blood sugar levels to rise or fall in those with and without diabetes. This means it is critical to know how the body will respond to food and exercise to avoid complications. Part of this may include paying attention to the glycemic index of a pre-exercise meal. Eating foods that have too high or too low of a glycemic index can lead to serious complications. To avoid complications, check with a doctor or registered dietitian about a personal food plan based on activity level and overall health.
Identification
The glycemic index involves assigning numbers to foods based on how fast they raise blood sugar levels after ingestion, according to the University of Wisconsin. A glycemic index over 70 is high and means that the food raises blood sugar levels quickly. A score of between 50 and 70 is considered medium, and less than 50 is considered low, because it does not cause spikes and drops in blood glucose levels. This is important because glucose is the body's main source of fuel during most forms of exercise. Spikes and drops in blood sugar levels can affect performance and may even be dangerous.
Considerations
The food you consume is eventually converted to glucose to be used by the cells. The hormone insulin must be present for the cells to use the glucose, according to the Family Doctor website. If blood sugar levels get too high, such as when you eat a high-glycemic food, the body may not be able to produce enough insulin to handle all of the blood sugar. In contrast, if you consume only low glycemic index foods before heavy exercise, blood glucose levels can plummet. This can happen in diabetics and non-diabetics. The concern is that both high and low blood sugar levels can become life-threatening you do not manage them properly.
Warnings
Exercise is an important component of an overall plan to manage blood sugar levels. For safety, the Mayo Clinic recommends that diabetics test their blood sugar levels before, during and after exercise to see how the body is responding. General guidelines are that if the blood sugar level is between 100 to 250 mg/dL, it is safe to exercise. If it is under 100 mg/dL, eat a high glycemic food, then wait 15 minutes and retest. Repeat this process until blood sugar levels are in a safer zone for exercise. If the reading is 250 mg/dL to 300 mg/dL, test your urine for ketones. If they are present, it is not safe to exercise. Exercise is never safe if blood sugar levels are 300 mg/dL or higher. Adjust your pre-exercise diet if your blood sugar levels are always too high or low.
Solution
Since each case of diabetes is different, each individual will need to formulate a specific plan. The Johns Hopkins website suggests learning to not only watch the glycemic index of foods before exercise but the timing of the meals as well. For most patients, the best time to exercise is one to three hours after a meal. Check your blood glucose levels once 30 minutes before working out and again just before starting. When you work out for more than an hour, check your blood sugar levels every 30 minutes. If the pre-exercise meal did not provide enough fuel and your blood sugar levels drop too low, stop exercising and have a snack. Talk to a physician about the best way to control levels that are too high.
Prevention/Solution
Blood sugar levels can climb too high if the exercise session is not strenuous enough to use up the glucose in the blood. This can lead to excessive thirst or hunger, and the situation may quickly become life-threatening, says the American Diabetes Association. Diabetes medication or insulin may be needed to control blood sugar levels. If the level of exercise is too strenuous and blood sugar levels drop, symptoms such as shakiness, fatigue, lack of muscle coordination and many others can occur. If this happens, consuming 1/2 cup of juice or regular soda or 2 tbsp. of raisins or four to five saltine crackers can help get blood sugar levels back to a healthy level. With time and experimentation, you can find the right food and exercise combination.
