Back to Sports Corner Blood Sugar Rises with Exercise

Why Does My Blood Sugar Go Up with Exercise or Competition?

Many people with Type 1 diabetes experience high blood sugars when they exercise or compete in their sport. This situation often frustrates athletes as well as the recreational exercise enthusiast. There are a couple of possibilities why this happens. If an insufficient amount of insulin is in the blood the blood sugar will rise. Adding exercise to the mix, especially anaerobic type of activities such as weight lifting, sprinting, or any sport requiring short intense spurts can cause a further increase in blood sugar. The low insulin levels joined with the secretion of hormones (i.e., epinephrine, norepinephrine, cortisol, growth hormone, and glucagon) cause the liver to release glucose into the blood sending blood sugar even higher. These hormones are called "stress" hormones and have the same affect on the body whether it is a physical stress, like exercise, or a mental one which can occur prior to an important athletic competition. Athletes who are very competitive often struggle to deal with this situation.

There is no easy solution to combat high blood sugars before, during, or even after exercise since each person's diabetes is individualized. There are techniques to try to help minimize the increase. For instance, as long as the healthcare team approves insulin may be used prior to the activity if levels are too high to start. It is recommended to be conservative with this approach since exercise and insulin can cause a rapid drop in blood sugar causing levels to go too low. If 1 unit of insulin usually drops the blood sugar 50 points try of a unit figuring on the same 50 point drop. The only way to determine the right amount of insulin to use is to check blood sugars more often and look for patterns rather than just one attempt. If high blood sugar is a problem during the event give the insulin ~30 mins prior to the start to give it time to work.

Another suggestion is to drink water when blood sugars are high. This helps in a couple of ways. It helps lower blood sugars and washes away ketones if they are present. It also helps hydrate the body which is often dehydrated due to high blood sugars. During strenuous exercise the blood sugar may merely rise due to dehydration. In this case simply drinking water will help return levels to normal without using insulin. Whether you have diabetes or not staying hydrated will help performance especially in the last part of games when fatigue plays a significant role in winning or losing. A good rule to follow is to drink two glasses (16oz) two hours prior to activity, one glass (8 oz) an half hour to an hour before and 4-6 oz every 15-20 minutes during activity.

For the competitive athlete who struggles with high blood sugars prior to most games due to the mental stress of the upcoming game try using stress management techniques. If the anxiety leading up to the competition can be reduces somewhat maybe a 320 mg/dl blood sugar now becomes a more manageable 250 mg/dl. A technique may be as simply as listening to music leading up to a game or more advanced techniques shown by Jack Broderick, (FITT, Inc., 2000) in the table below.

Develop a Strategy for Coping with Stress
Positive Mental Imagery.
One of your best strategies is positive mental imagery. We use mental imagery all the time. When we are stressed, we imagine the worst. We wake up fatigued because of worrying through the night; we picture the frustrating drive to work; we see our over-loaded desk; we anticipate negative interactions all day. That's negative mental imagery.
Learn to use positive mental imagery.
Instead of lying in bed worrying, picture one of the nicest, most restful places you've ever been. Imagine yourself in that place-recall the place in vivid detail-until you fall asleep. Discipline your mind-when you drift back into negative thoughts, gently bring yourself back to the restful place. The idea is to replace your habits of worry. When you are calm, replace the negative thoughts with positive images. Imagine yourself dealing with the challenges of the day in a successful way. Create a solution for the challenges that come your way. Imagine yourself feeling like a winner.
Muscle Relaxation.
Do you have a chronically tense neck, shoulders, or jaw? Do you grind your teeth at night? Use muscle relaxation techniques to release this stress reaction. Reprogram your muscles. Focus on your upper body. "Scan" your neck-become aware of how it feels. Tighten the muscles in your neck (not too tight, just a moderate increase in tension) for 3 to 5 seconds, then slowly relax. Next focus on your shoulders. Continue this exercise from the crown of your head to your belly button. To release tension in your lower body, start with your toes and work up to your belly button.
Deep Breathing.
Most of us are shallow breathers. The stress in our lives causes us to breathe shallow, rapid breaths through our mouths-a mild fight-or-flight response. Deep breathing (belly breathing) helps us slow down and relax, changes the pH in our blood, and negates the flight-or-fight response. Take a three-minute break. Focus on your breathing. Relax your stomach as you slowly take in a deep breath-try counting to 5 as you inhale. Momentarily hold your breath-2 to 3 seconds. Then slowly exhale-feel your chest sinking down as you start to relax. Over a period of three minutes, continue breathing deeply as a relaxed pace.
Another breathing technique is to focus on the breath leaving your lungs. As you exhale, feel the warm air leave your body. Each time you exhale, clean your mind-release stress and worry-thoughts-as you focus on your breath.

In summary, high blood sugars will happen with competitive athletes and more likely in intense sports or activities. Checking blood sugars before, during and after activity will identify patterns to help make positive changes. The guidelines for delaying exercise due to high blood sugars are: 250 mg/dl to 300 mg/dl with ketones or 300+ mg/dl with or without ketones. The goal is to minimize the extremes by implementing the ideas mentioned above and as always include the healthcare team on any changes to your diabetes management.

Rick Philbin, MBA, M.Ed., ATC

March 2007

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