What Is It?

Type 1 diabetes (T1D) is believed to be caused by the body mistakenly attacking itself and particularly the cells (beta cells) in the pancreas that make insulin. This insulin deficiency causes imbalance in the individuals blood sugar levels and is often managed by dietary changes and injected insulin after consultation with a healthcare specialist.

It is usually diagnosed in children, teens and young adults and is less common than type 2 diabetes. Five to 10 percent of diabetics have T1D and that varies based upon age, gender, family history, ethnicity and geography. Although exercise presents several important challenges to diabetes management, the importance of physical activity has great benefits to long-term health.

Symptoms

• Hypoglycemia (low blood sugar) can cause fatigue, excess sweating, hunger, fast heartbeat, shakiness, nausea, vomiting, unsteadiness, confusion.

• Hyperglycemia (high blood sugar) can cause frequent urination, increased thirst, blurred vision, fatigue, headache, vomiting, deep and labored breathing and confusion.

Sports Medicine Evaluation / Treatment

Athletes with a diagnosis of T1D should seek further evaluation by a physician to prevent experiencing the symptoms described above. The risk of hypoglycemia is affected by the type, duration and intensity of physical activity. For example, a moderate-paced run or swim will likely reduce blood sugar. On the other hand, a short, all-out sprint or weight lifting can raise blood sugar levels because they trigger a response in the body from hormones that release stored glucose from the liver.

Hyperglycemia can also be caused during a competition, due to psychological stress, in warm and humid environments and when there are errors in insulin and dietary management. A sports medicine physician will perform a thorough history and physical exam, looking for controllable factors in the patient’s exercise regimen. Blood sugar will also be checked before exercise. If the blood sugar is high before exercise, the patient’s blood or urine will be checked for ketones. If the test is positive, vigorous activity must be avoided.

The physician will provide patient with a glucometer to measure blood sugar at home and ask them to keep a blood sugar log, including the patient’s insulin regimen, dietary habits as well as their exercise schedule with measurements of blood sugar before, during and after an exercise session. Based on that data, adjustments will be suggested to refine the athlete’s plan. If chronic lows or highs are noted, insulin dose changes or a meal plan may be initiated.

Prevention

The best way to prevent the associated symptoms of hypoglycemia is to always carry a snack or drink (like juice or glucose tabs) that will quickly raise your blood sugar. Post-exercise recovery drinks can also be an effective tool to avoid immediate hypoglycemia. An athlete with T1D might need to start preparing an hour or two before beginning an activity to ensure that his or her insulin is balanced at an appropriate level. Late snacks or adjusting basal insulin infusions before bedtime can prevent delayed hypoglycemia (commonly occurs 7 to 11 hours after physical activity). Consultation with a sports medicine physician is necessary, as well as self-monitoring in response to different activities. An individualized regimen will also be created for the athlete that will allow them to exercise without extreme fluctuations in their blood sugar levels.

Return to Play

Sports medicine physicians reinforce to people with T1D that commitment to a healthy, active lifestyle may help them reduce risk of certain diseases, lower daily insulin requirements, prevent diabetic complications and have a higher quality of life. Once a safe plan has been put in place, return to full activity is a shared decision between the physician, the athlete and many times the athlete’s family. Follow-up visits are encouraged to ensure compliance and allow the doctor to monitor blood sugar in response to exercise during the season.

AMSSM Member Authors
Ioannis N. Liras, MD, and George N. Liras, DO

References
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4. Riddell M, Perkins BA. Exercise and glucose metabolism in persons with diabetes mellitus: perspectives on the role for continuous glucose monitoring. J Diabetes Sci Technol. 2009; 3:914-923.