Alisha, a fourth-grader, told her physical education teacher that she had diabetes and needed to test her blood sugar level. The teacher told her to wait until later and return immediately to finish the parachute activity. A few minutes after rejoining the class Alisha collapsed. Alisha's physical education teacher did not understand diabetes and the dangers of having a low blood sugar level.
This dangerous scenario could occur if the physical educator does not understand diabetes and the necessary steps for providing safe and successful experiences for students with diabetes. This article will provide the physical educator with an understanding of diabetes and important considerations when teaching physical education to students with diabetes. In this article we discuss four aspects of diabetes: an overview; common questions and answers concerning the control of diabetes; balancing insulin, food intake, and physical activity; and implications for the physical education professional.
Overview of Diabetes
Diabetes, a major national health problem, is now recognized as the third leading cause of death in the United States. People with diabetes have an increased risk of heart attack, stroke, kidney disease, blindness, and gangrene. More than 14 million Americans currently have been diagnosed with diabetes and an estimated 2 million people have diabetes but are not diagnosed. In addition, approximately one in 600 school-age children have diabetes.
Diabetes is a chronic metabolic disease that interferes with the body's ability to produce or use insulin or both. The body fails to burn carbohydrate intake properly, so glucose accumulates in the bloodstream. This condition is known as hyperglycemia, an overabundance of blood sugar. The name diabetes mellitus means literally "sweet urine" and refers to an overabundance of blood sugar in the urine of the uncontrolled diabetic.
A simplified cycle of normal glucose metabolism is shown in figure 1. As the cycle begins, food is consumed and digested (Phase I). Most of the food is converted to glucose and the blood sugar level in the bloodstream rises (Phase II). The increased blood sugar results in the secretion of insulin by the pancreas (Phase III). The insulin enables the glucose to enter the body's cells, providing energy for the body to perform normal functions (Phase IV). As the insulin acts on the raised blood sugar, the food intake is metabolized and broken down into usable form and can be used by the cells of the body, thus decreasing the blood sugar level to a normal range (Phase V) [ILLUSTRATION FOR FIGURE 1 OMITTED].
Diabetes results from the body's inability to produce or use insulin. Little or no insulin is secreted from the pancreas. The result is that glucose is unable to enter the body's cells and the body cannot perform normal functions. As glucose remains unused in the bloodstream, continuing to add to the blood sugar level, the body's cells begin to rely on converting stored fat cells into energy. As this continues, ketone bodies - waste products that result from fat metabolism - accumulate in the bloodstream and are eliminated from the body through the kidneys, spilling over into the urine. In uncontrolled diabetes, the concentration of ketones becomes very high and a strong acid effect known as ketoacidosis occurs (Eichstaedt & Kalakian, 1993; Sherrill, 1993). Ketoacidosis, if left untreated, can lead to death.
The Two Types of Diabetes
Diabetes is categorized into two groups: Type I and Type II. In Type I, known as insulin-dependent diabetes mellitus (IDDM), the pancreas produces little or no insulin. The Type I diabetic needs to administer insulin to properly use glucose and thus remain alive. Type I has a rapid onset that typically occurs in childhood or adolescence.
In Type II diabetes, known as non-insulin dependent diabetes mellitus (NIDDM), the pancreas does produce insulin; however, the insulin does not function properly. The Type II diabetic can control his or her diabetes through diet, exercise, and/or oral hypoglycemics. Type II diabetes has a slow onset and usually occurs in individuals over 40 years of age.
Although Type I occurs less frequently than Type II, Type I is the classification most physical educators will encounter in their professional settings. Thus, Type I diabetes is the focus of this article.
Common Questions and Answers Concerning Diabetes
The major goal of the student with diabetes is to maintain a blood sugar level as close to normal as possible. The following question-and-answer section provides the physical educator with information about normal blood sugar levels; fluctuations in blood sugar levels; and balancing insulin, food intake, and physical activity to maintain a normal blood sugar level.
Why is maintaining a normal blood sugar level important?
First, the student who maintains normal blood sugar levels will feel better and will be able to carry out daily activities with vigor. Second, the long-term complications of diabetes can be prevented or delayed by maintaining blood sugar levels as close to normal as possible. A long-term study found that well-controlled blood sugar levels reduced damage to eyes, kidneys, and nerves by approximately 60 percent (McCarren, 1993).
What is a normal blood sugar level?
In a person without diabetes a normal blood sugar level is between 70120 milligrams per deciliter (mg/dl). The desirable range for blood sugar levels in the student with diabetes is as close as possible to 70-120 mg/dl before meals and less than 180 mg/dl two hours after meals.
How is self monitoring blood sugar done?
The student with diabetes monitors his or her blood sugar level by using a self-monitoring blood glucose (SMBG) meter, which is a portable blood analyzer [ILLUSTRATION FOR FIGURE 2 OMITTED] and which comes in many models and sizes. A finger-stick (capillary) sample of blood is placed on a strip that is inserted into the meter. The blood sugar level is displayed within 15 seconds to 2 minutes, depending upon the brand of meter (Keegan et al., 1993a).
How much can blood sugar levels fluctuate?
Drastic fluctuations in blood sugar levels can occur in students with diabetes, especially in those students who participate in physical activity. A blood sugar level below the normal range ([less than]70 mg/dl) is called hypoglycemia, or an insulin reaction. A blood sugar above the normal range ([greater than]120 mg/dl) is called hyperglycemia. Because hypoglycemia and hyperglycemia have causes and treatments that are exactly the opposite of each other, it is important to distinguish between the two. It is important however to remember that the symptoms for each do overlap and can be confusing. That is why students should test their blood sugar levels.
What is hypoglycemia or an insulin reaction?
Hypoglycemia (an insulin reaction) is characterized by a blood sugar level below 70 mg/dl. One of the major dangers associated with an insulin reaction is that the brain relies on glucose as its only source of fuel; therefore, a prolonged low blood sugar level may adversely affect brain function, causing confusion, irritability, and slower motor skill function. Hypoglycemia is the most significant problem for the student with diabetes who participates in physical activity (Galbo, 1988; Wallberg-Henriksson, 1992). An insulin reaction occurs quickly, with symptoms appearing within a period of minutes and up to an hour. A mild reaction can be annoying and embarrassing while a severe reaction is dangerous, and can be life threatening. An insulin reaction can be caused by too much insulin, inadequate consumption of carbohydrates, increased physical activity, or any combination.
What are the warning signs of an insulin reaction?
The student will feel ill during an insulin reaction. The most common warning signs are anxiety and sweating; however, the student may also exhibit one or more of the warning signs listed in table 1. Insulin reactions can occur without symptoms, with only minor symptoms, or with full-blown symptoms. The type and degree of symptoms will also vary depending upon the speed or severity of the reaction. The student may recognize some of the symptoms, while other symptoms may not be recognized. Peers, parents or teachers may observe the symptoms before the student does.
What is the treatment for an insulin reaction?
Although prevention is the best treatment, not even the most conscientious student can always prevent an insulin reaction. When a reaction does occur, the student needs some form of sugar to elevate his or her blood sugar level back to normal. Glucose, or sugar, comes in many forms - soda, orange juice, candy, or anything else that is sweet. Usually the student is capable of ingesting the sugar; however, if the student is unconscious (insulin shock) or otherwise unable to eat, glucagon (pure glucose in liquid form) is injected by someone trained in this procedure. The amount of glucose necessary during an insulin reaction to bring the blood sugar level back up to normal will vary depending on the individual and the circumstances surrounding the reaction. Generally, simple carbohydrates such as fruit juice, raisins, sugar cubes, or a couple of pieces of hard candy will quickly raise the blood sugar level 40 to 60 mg/dl. In addition to sugary foods, there are also commercially manufactured products such as glucose tablets designed to treat insulin reactions.
What is hyperglycemia?
Hyperglycemia is a blood sugar level above 180 mg/dl and occurs when there is not enough insulin in the body to allow adequate glucose to enter the body's cells. Without the insulin to permit the burning of sugar into usable energy, the body begins to primarily burn fats and proteins. This causes large amounts of ketones to form. Ketones are chemicals normally produced in the liver from incomplete burning of acids derived from fats and proteins. When the blood sugar level reaches 240 mg/dl, the student should test his or her urine for ketones. Activity should not be performed if ketones are present. Because of the high level of acidity in the bloodstream, further exercise may only worsen the condition. Hyperglycemia occurs more slowly than an insulin reaction; it may occur over a period of several hours or several days.
What are the warning signs and treatment of hyperglycemia?
The student will not feel healthy when his or her blood sugar level is high. Extreme thirst, frequent urination, and fatigue are the most common warning signs. Table 2 lists common warning signs of high blood sugar.
Hyperglycemia is treated by administering insulin; however, because hyperglycemia usually occurs at a much slower rate than hypoglycemia (sometimes over a period of several days), the physical educator will rarely be involved in treating hyperglycemia. If hyperglycemia goes untreated, it will lead to a diabetic coma (unconsciousness) and eventually death (Davidson, 1981).
Balancing Insulin, Food Intake and Physical Activity
The major goal of the student with diabetes is to maintain a blood sugar level as close to normal as possible. Throughout the day, wide fluctuations in the blood sugar level, both below and above the normal level, can occur. Three major factors that influence fluctuations are insulin, food intake (primarily carbohydrate), and physical activity.
How does insulin work?
Insulin has time-of-action characteristics based on how soon after infusion the insulin affects the blood sugar level. These time-of-action characteristics are:
* Onset: The time it takes for the insulin to reach the bloodstream and begin to lower the blood sugar level.
* Peak: The time during which insulin is at its maximum strength in terms of lowering the blood sugar level.
* Duration: The total length of time the insulin continues to lower the blood sugar level.
Three categories of insulin are based upon the time-of-action characteristics of the insulin.
* Short-acting insulin: It has the fastest onset and peak and the shortest duration.
* Intermediate-acting insulin: The onset and the peak take longer to occur, and the peak and duration last for a greater period of time.
* Long-acting insulin: It has the slowest onset, little or no peak, and the longest duration.
How is insulin infused into the body?
Insulin can be infused into the body in two ways: injection therapy or insulin pump therapy. Insulin cannot be taken orally because digestive juices in the stomach destroy insulin before it can be absorbed into the bloodstream.
The use of injections (shots) is the most common method of insulin infusion. Insulin injections are usually self-administered by the diabetic and given with a disposable syringe, or a syringe alternative such as a jet injector, pen, or infuser. Injection sites may include the stomach, thigh, hip, arm, buttocks, or leg areas. A student with diabetes on injection therapy may use one or more of the three insulin categories - short, intermediate, long acting. The number of injections per day may vary from one to six (Keegan et al., 1993b).
A relatively new method of insulin infusion is the insulin infusion pump. The pump is a miniature, computerized pump, about the size of a pager. It can be worn on a belt or placed in a pocket [ILLUSTRATION FOR FIGURE 3 OMITTED].
The pump uses only short-acting human insulin and can release an incredibly small dose of insulin continuously; these two features allow the pump to closely mimic the body's normal release of insulin. The insulin pump infuses insulin into the body in two ways (Walsh & Roberts, 1989).
* Basal rate: a preprogrammed amount of insulin infused continuously to maintain a normal metabolic state when not eating.
* Bolus: a programmed amount of insulin infused before food is consumed and when the blood sugar is too high.
How Does Food Intake Affect Blood Sugar Level?
As stated earlier, the ingestion of food raises the blood sugar level. Insulin, infused via injections or the pump, is required to bring the glucose level back down to normal levels after food is ingested. Of the three nutrients, carbohydrates, fats, and proteins, carbohydrates have the greatest affect on blood sugar level.
How is insulin used to bring blood sugar back down after ingesting food?
The type of insulin infusion therapy used will determined how the insulin brings down the rise in blood sugar level resulting from eating food. (For specific dietary guidelines for diabetics, see American Diabetes Association, 1993).
* Injection Therapy. With insulin shots, the student's eating schedule for an entire day will be dictated by the time of the morning shot, the type(s) of insulin (short, intermediate, long acting), and the amount (number of units) of insulin. A student on insulin shots involving intermediate or long-acting insulin must eat the right amount of the right foods at the right time.
* Pump Therapy. The insulin pump allows the student more freedom for meal times and types of food eaten than insulin shots. The basal rate provides the insulin necessary for the student to carry out normal, daily activities. When the student chooses to eat, a bolus of insulin is programmed to cover the carbohydrate content of the meal. The basal rate and bolus features of the pump allow the pump user to eat at any time; a meal can even be skipped if desired.
How does physical activity affect blood sugar level?
Most often, physical activity lowers blood sugar. However, very vigorous, high-intensity activity can cause an increase in blood sugar level, if the blood sugar level is high ([greater than]240 mg/dl) just before the activity.
Why does physical activity lower blood sugar? Physical activity lowers blood sugar as the physical activity burns up sugar available in the body; it also causes insulin to be absorbed at a faster rate. Additionally, an insulin shot taken in a muscle area that is used during physical activity will cause the insulin to be absorbed at an even faster rate. This increase in the rate of insulin absorption may cause early peaking of the insulin and cause a sudden lowering of blood sugar, resulting in an insulin reaction (Kovisto & Felig, 1978). The lowering effect of physical activity on blood sugar may last for 16 to 24 hours. Thus, to prevent hypoglycemia, additional blood sugar monitoring is necessary during the 24-hour period following vigorous exercise.
What adjustments in food intake and insulin can prevent sudden drops in blood sugar during physical activity?
Adjustments are necessary to prevent a sudden drop in blood sugar level during and following physical activity. Tables 3 and 4 present guidelines aimed at preventing an insulin reaction during physical activity for the student on injection therapy (Vitug, Schneider, & Ruderman, 1988) and pump therapy (Walsh & Roberts, 1989), respectively.
Implications for the Physical Education Professional
Once the physical educator understands diabetes, he or she can provide safe and positive physical education experiences for students with diabetes. Professionals in physical education can enhance the physical education experience for the student with diabetes by implementing certain practices (see table 5).
Identify students with diabetes
Through communication with the school nurse the physical educator can identify students with diabetes. Additionally, some students who have diabetes may be undiagnosed; thus it is important the physical educator is aware of the common symptoms of diabetes such as excess thirst, frequent urination, hunger, and fatigue (see table 2). Physical educators should refer students exhibiting symptoms of diabetes to the school nurse.
Meet with the student, family, and school nurse
Discuss each student's sites and method of injecting insulin, dosage, eating habits, and physical activity patterns with the student, family, and school nurse. If possible, include the physician/health care team. Also discuss how often the student tests blood sugar levels and his or her record keeping habits. The student should be taught to avoid injecting his or her insulin into the muscle area that will be heavily used during physical education that day. This will prevent the insulin from being absorbed at an even faster rate, causing an insulin reaction.
Learn to measure blood sugar
Whenever possible, learn how to use a self-monitoring blood sugar. meter to measure the student's blood sugar level [ILLUSTRATION FOR FIGURE 2 OMITTED]. In an emergency, it may be necessary for the physical educator to test the student's blood sugar.
Ask the student to measure blood sugar level before, during, and after physical activity
Ask the student to report his or her blood sugar level when beginning class. The student should measure the blood sugar level 60 minutes, 30 minutes, and immediately prior to physical education class. If the blood sugar level is below 100 mg/dl or has dropped more than 50 mg/dl during the 60 minutes prior to class, the Student should eat a snack. If the blood sugar level is 240 mg/(dl or higher the student should test lot ketones; if ketches are present the student should not participate in activity.
Encourage the student to keep a daily log
Encourage students in the fourth grade and above to keep a daily log of blood sugar levels (time and level), insulin (type, amount, time, and amount of last injection or bolus and amount), food intake (time and type of food consumed for meals and for snacks), and physical activity (time, intensity, and duration). This daily log assists the student in keeping blood sugar levels as close to normal as possible (see table 6). Record keeping by the student will also provide the student, family, school nurse, and physician/health care team with the information necessary to adjust food intake and insulin dosage.
Coordinate physical education class time with food and insulin intake
The student's physical education (class should not be scheduled during the time period during which insulin is at its peak or just prior to a meal or snack. Students should not take a physical education class within one-and-one-half hours of an injection or bolus; when possible, students should take a physical education class immediately following breakfast or lunch. Strenuous physical activity with little or no food intake can cause an insulin reaction.
Notify the student in advance of activity level changes
Alert the student ahead of time about changes in the duration or intensity level of physical activity in class. For example, notify the student in advance when fitness testing will occur so food or insulin intake can be adjusted accordingly.
Know the warning signs of an insulin reaction Discuss with the student the warning [TABULAR DATA FOR TABLE 6 OMITTED] signs of an insulin reaction. Remember, each student with diabetes may exhibit different symptoms of an insulin reaction; discuss the symptoms commonly exhibited by the student (see table 2).
Have the student keep a carbohydrate snack nearby
Encourage the student to carry a snack consisting of simple carbohydrates. The student with diabetes has primary responsibility for controlling his or her blood sugar level; however, the physical educator should keep on Kite simple carbohydrates such as glucose tablets or fruit juice in case of an emergency.
Encourage the student to increase fluid intake
The student should increase fluid intake 75 to 30 minutes prior to vigorous activity. Students with diabetes are particularly susceptible to dehydration when exercising on warm days. Blood glucose levels above 180 mg/dl draw water from the body's tissues. Water is the recommended fluid. During physical activity it should be taken every 15 minutes.
Encourage activity progression at the student's own rate
During the initial phase of a new program, the student may experience an adjustment period in balancing insulin, food intake, and physical activity. The student with diabetes should exercise at a rate that Feels comfortable. This rate can be determined by discussing the matter with the student, family, school nurse, and physician/health care team. The physical educator can play an important role in assisting the student to become aware of his or her comfort zone during activity.
Encourage the student to pay close attention to skin care
Encourage the student to pay close attention to skin care especially in the area of the feet. In persons with diabetes there is a tendency for blood vessels to prematurely thicken or harden resulting in restricted blood flow. Damage can occur without any signs of pain or inflammation. Properly fitting shoes and stocks should be worn. If a blister develops, it should be attended to immediately and weight bearing exercise should be prohibited until the foot completely heals (Rimmer, 1994).
Understand and respect the student with diabetes
Understand and respect the student's special needs and provide the necessary support. Students with diabetes can, and should be, as active and fit as other students (Kertzer et al., 1994). On occasion, the student may need to be briefly excused from class to measure blood sugar levels, take glucose, or inject insulin.
While these guidelines provide the physical educator with an understanding of adjustments that can be made to compensate for decreases in blood sugar level (luring physical activity, such adjustments are very individualistic. A physical educator who understands and is aware of what diabetes entails can provide students with diabetes the opportunity to safely participate in physical education and to enjoy the benefits of physical activity. Students with diabetes, like all other students, should be encouraged to lead an active lifestyle.
American Diabetes Association. (1993). Position statement: Nutritional recommendations and principles for individuals with diabetes mellitus. Diabetes Care, 16, 22-29.
Davidson, M. B. (1981). Diabetes, diagnosis and treatment, (vol 1). New York: Wiley Medical Publications.
Eichstaedt, C. B., & Kalakian, L. H. (1993). Developmental/adapted physical education (3rd ed.). New York: Macmillan.
Galbo, H. (1988). Exercise and diabetes. Scandinavian Journal of Sports Sciences, 10, 89-95.
Keegan, A., McCarren, M., Walker, J., & Walsh, P. (1993a). Blood sugar level monitors and data management. Diabetes Forecast, 46(10), 60-67.
Keegan, A., McCarren, M., Walker, J., & Walsh, P. (1993b). Insulin delivery. Diabetes Forecast, 46(10), 53-58.
Kertzer, R., Croce, R., Hinkle, R., & Janson-Sand, C. (1994). Selected fitness and motor behavior parameters of children with insulin-dependent diabetes mellitus. Adapted Physical Activity Quarterly, 11, 284-296.
Kovisto, V. A., & Felig, P. (1978). Effects of leg exercise on insulin absorption in diabetic patients. New England Journal of Medicine, 298, 79-83.
McCarren, M. (1993). DCCT: Intensive therapy reduces the risk of diabetic eye, kidney, and nerve disease. Diabetes Forecast, 46(9), 49-51.
Rimmer, J. H. (1994). Fitness and rehabilitation programs for special populations. Dubuque IA: WCB Brown & Benchmark.
Sherrill, C. (1993). Adapted physical activity, recreation and sport (4th ed.). Dubuque, IA: WCB Brown & Benchmark.
Vitug, A., Schneider, S., & Ruderman, N. (1988). Exercise and Type I Diabetes Mellitus. Exercise and Sport Science Reviews, 16, 285-304.
Wallberg-Henriksson, H. (1992). Exercise and diabetes mellitus. In J. O. Holloszy (Ed.), Exercise and Sport Sciences Reviews, (02): 339-368. Baltimore: Williams and Wilkins.
Walsh, J., & Roberts, R. (1989). Pumping insulin. Sylmar, CA: Minimed Technologies.
Table 1. Common Warning Signs of an Insulin Reaction
* Blurred vision
* Elevated heart rate
* Convulsions, loss of consciousness, and even death if glucose is not given
Table 2. Common Warning Signs of Hyperglycemia
* Frequent urination
* Extreme thirst
* Fruity-smelling breath
* Unconsciousness, and even death if insulin is not administered
Table 3. Injection Therapy: Guidelines for Avoiding an Insulin Reaction During Exercise
* Increase carbohydrate intake.
* Consume an additional 15 grams of carbohydrate prior to exercise.
* Consume 15 to 30 grams of carbohydrate for every 30 minutes of moderately-intense exercise.
* Consume a snack of slowly absorbed carbohydrate following prolonged (more than 60 minutes) exercise.
* Decrease insulin dose.
* Avoid exercise during insulin peaks; avoid exercise prior to meals.
* Avoid injecting insulin into major muscle areas to be exercised.
* Avoid exercising within 1 1/2 hours following an injection.
* If the blood glucose level is below 100 mg/dl, consume additional carbohydrates prior to exercise.
Table 4. Pump Therapy: Guidelines for Avoiding an Insulin Reaction During Exercise
* For vigorous activity that occurs within 2 hours after a meal, decrease the bolus for that meal by 30% to 50%.
* For vigorous activity that occurs more than 2 hours after a meal, consume extra carbohydrates rather than decreasing the bolus for the previous meal.
* For vigorous activity of a high intensity or long duration, lower the basal rate before, during, and after exercise.
* If the blood glucose level is below 100 mg/dl, consume carbohydrates prior to exercise.
Table 5. Considerations for Teaching Physical Education to the Student with Diabetes
* Identify students with diabetes
* Meet with the student, family, and school nurse
* Learn to measure blood sugar level
* Instruct the student to measure blood sugar level before, during, and after physical activity
* Encourage the student to keep a daily log of blood sugar levels, insulin, food intake, and physical activity
* Coordinate the physical education class time with food and insulin intake
* Notify the student in advance of changes in activity level
* Know the warning signs of an insulin reaction
* Instruct the student to keep a carbohydrate snack nearby
* Encourage the student to increase fluid intake
* Encourage activity progression at student's own rate
* Encourage student to pay close attention to skin care
* Understand and respect the student with diabetes
Clayre Petray is a professor, Keith Freesemann is an associate professor, and Barry Lavay is a professor in the Department of Kinesiology and Physical Education at California State University, Long Beach, CA 90840.…