October 2008 Issue

Exercise for Diabetes Prevention and Treatment
By Dino Pierce, CFT, CPT, RD, CDE
Today’s Dietitian
Vol. 10 No. 10 P. 8

Suggested CDR Learning Codes: 4060, 5190; Level 2

The Diabetes Prevention Program has announced the results of a large clinical trial indicating that at least 10 million Americans are at risk for developing type 2 diabetes. Recently, the Centers for Disease Control and Prevention released data from 2007 stating that 24 million Americans have diabetes and estimating that 57 million Americans have prediabetes. The need for energetic intervention to forestall the effects of this looming pandemic should be evident to all health professionals.

Exercise is an effective tool for preventing type 2 diabetes and potential diabetic complications. Additionally, exercise promotes weight loss and maintenance, helps with stress management, and sensitizes muscle and hepatic cells to facilitate glucose uptake and increase insulin sensitivity. Americans can reduce their risk of developing type 2 diabetes by 58% by eating healthfully and exercising at moderate intensity for 30 minutes each day. Likewise, calorie restriction can reduce body weight by 5% to 7%, yielding a 60% risk reduction.1

It is never too late to start an exercise regimen. However, it must be individualized to maximize rewards and minimize hazards. The goal of this article is to provide exercise guidelines and considerations to help manage type 2 diabetes and prevent it in high-risk individuals.

Exercise Recommendations
In addition to improving blood glucose control, regular physical activity helps reduce the risk of cardiovascular disease (CVD) and facilitates weight management.

The American Diabetes Association and American Heart Association provide the following exercise recommendations for individuals with type 2 diabetes2,3:

• At least 150 minutes per week should be devoted to moderate-intensity aerobic physical activity (40% to 60% of maximal oxygen consumption [VO2max] or 50% to 70% of maximum heart rate) and/or at least 90 minutes per week of vigorous aerobic exercise (above 60% of VO2max or above 70% of maximum heart rate). The physical activity should be distributed over at least three days per week and with no more than two consecutive days without physical activity.

• In the absence of contraindications, people with type 2 diabetes should perform resistance exercises three times per week, targeting all major muscle groups and progressing to three sets of eight to 10 repetitions at a weight that cannot be lifted more than eight to 10 times. Initial supervision and periodic reassessments by a qualified exercise specialist are recommended.

• Four or more hours per week of moderate-to-vigorous aerobic and/or resistance exercise should be performed as it is associated with greater CVD risk reduction compared with lower volumes of activity.

• For long-term maintenance of major weight loss (30 pounds [13.6 kilograms] or more), more exercise (seven hours per week of moderate or vigorous aerobic physical activity) may be helpful.

A thorough medical evaluation and clearance from a physician are necessary before beginning a program more vigorous than brisk walking. Previously sedentary patients should embark on any activity program cautiously.

Walking, doing yard work, and dancing are sound entry-level activities for most people and are unlikely to have adverse consequences beyond sore muscles. As their fitness levels improve, patients should add a few minutes to their program. Instruct patients to stop exercising if they feel pain. If the pain fails to subside, encourage them to inform a healthcare professional immediately. Sometimes early enthusiasm leads patients to attempt too much too soon.

Pleasurable activities increase compliance. Recommend that patients exercise with family or friends, as this provides accountability and helps ensure safety during exercise. The intensity of the activity required to reduce the risk of chronic disease should not feel like competition or work. If patients want to participate in a competitive sporting event or increase their level of activity, they should work with a professional to develop an appropriate training regimen.

Physiologic Issues and Blood Glucose Control
During moderate-intensity exercise (65% of VO2max), in people with normal glucose tolerance, muscle glycogen and plasma glucose supply about one half of the energy expended with the remainder coming from fat oxidation. Plasma free fatty acids and intramuscular triglycerides initially contribute equally to total fat oxidation during moderate-intensity exercise. During high-intensity exercise (85% of VO2max), muscle glycogen and blood glucose provide more than two thirds of the needed energy, with the remainder coming from plasma fatty acids and intramuscular triglycerides. Blood glucose becomes an increasingly important source of carbohydrate as muscle glycogen stores decline.

In individuals without diabetes, exercise-induced hypoglycemia is rare, as hormonally driven metabolic adjustments maintain normal blood glucose levels. Exercise increases secretion of the catecholamines (epinephrine and norepinephrine) and glucagon. These hormones raise blood glucose by blocking the release of insulin and promoting liver glycogenolysis and gluconeogenesis.

Blood glucose management is essential to maintain physiological homeostasis and central nervous system function in individuals with diabetes. However, the regulatory mechanisms that maintain normoglycemia are inoperative in persons with type 1 diabetes. If a person with type 1 diabetes has a small amount of insulin in the blood due to inadequate insulin therapy, the secretion of catecholamines and glucagon can cause high blood glucose levels during exercise. If untreated, ketone bodies can accumulate and diabetic ketoacidosis can occur. Conversely, if there are high levels of insulin due to excessive insulin therapy, a rapid drop in blood glucose can occur during exercise.
 
Similar concerns exist for individuals with type 2 diabetes using insulin, sulfonylureas, and/or meglitinides. As exercise has a potent insulinlike effect on glucose uptake by the muscle and increases insulin sensitivity, hypoglycemia can occur during prolonged exercise when exogenous insulin levels are at their peak.4
 
Exercise is therapeutic for all individuals, but healthcare professionals must understand the benefits and risks of exercises for their patients. Certified diabetes educators (CDEs), physicians, nurses, RDs, mental health professionals, and personal trainers will all benefit from possessing knowledge in exercise physiology.5
 
Before starting an exercise program, patients with diabetes should undergo medical evaluation for macrovascular and microvascular complications that exercise can exacerbate. A medical history questionnaire and assessment also encourages patients to disclose and discuss signs and symptoms of diseases affecting the cardiovascular system, eyes, kidneys, skin, and nervous system.5
 
Assessing the Cardiovascular System
A graded exercise test with electrocardiogram monitoring should be considered before previously sedentary individuals with diabetes whose 10-year risk of a coronary event is likely to be greater than 10% initiate aerobic activity more intense than brisk walking.
Stress tests are usually not recommended to detect coronary ischemia in asymptomatic individuals at low coronary risk (less than 10% risk of a cardiac event over 10 years). Clinical judgment should be used to determine whether an exercise stress test is necessary for patients participating in low-intensity exercises (below 60% of maximal heart rate) such as walking, leisurely bike rides, or low-impact water aerobics. Patients can be considered high risk for CVD and require a stress test if they exhibit one of the following5:

• older than the age of 35;

• diagnosis of type 2 diabetes for more than 10 years;

• diagnosis of type 1 diabetes for more than 15 years;

• presence of risk factors for coronary heart disease (CHD);

• presence of microvascular disease;

• presence of peripheral vascular disease (PVD); or

• presence of autonomic neuropathy.

Patients with CHD should undergo appropriate evaluations to determine their cardiovascular response to exercise. If they have cardiac complications, a medical evaluation is required to determine adequate circulation during exercise. Heartbeat and systolic function at rest and during exercise must be quantified to establish the proper frequency, intensity, and duration of exercise.

Preexisting Diabetic Complications
To reduce the risk of injury and medical complications, consider precautions associated with exercise. Since exercise increases insulin sensitivity and reduces blood glucose levels, a normal dose of an oral hypoglycemic agent may be too powerful, causing hypoglycemia during or after exercise. The following points discuss complications that individuals with diabetes routinely experience.4

• PVD: Patients with PVD are at risk for CVD and require medical evaluation prior to exercising. Signs and symptoms of PVD include intermittent claudication (severe pain in the calves while walking), alopecia, cold feet, weak or absent pulse in the feet, numbness and tingling, weak legs, burning or aching in the feet and toes, slow-healing leg and foot abrasions, and discoloration in the legs leading down to the toes.4-6

• Diabetic retinopathy: Retinopathy is classified as nonproliferative or proliferative diabetic retinopathy and progresses from mild to severe within those classifications. Severe retinopathy is a risk factor for CVD.

With nonproliferative diabetic retinopathy, the intraocular vessels leak fluid into the retina, triggering blurry vision. With proliferative diabetic retinopathy, delicate eye vessels are susceptible to perforation and bleeding, causing scarring and vision loss. The degree of retinopathy determines the risks affiliated with particular activities and must be known to prescribe exercise safely. Patients with proliferative diabetic retinopathy have the strictest exercise restrictions.4,7

In the absence of diabetic retinopathy, patients can engage in any exercise; however, it is imperative to have an annual eye exam. The presence of mild nonproliferative diabetic retinopathy indicates that all exercises are safe; however, an eye exam is recommended every six to 12 months. In moderate nonproliferative diabetic retinopathy, most exercises are acceptable, but those that cause a Valsalva maneuver (a forceful attempt at expiration against a closed airway [think of straining to lift a heavy object]) should be avoided, and an eye exam is necessary every four to six months. With severe nonproliferative diabetic retinopathy, the patient should avoid power lifting, Valsalva maneuvers, and active jarring exercises (eg, boxing, karate, football) and have an eye exam every two to four months.4,8

Numerous exercises are safe for patients with proliferative diabetic retinopathy, but they should use extreme caution with strenuous activity and avoid heavy weight lifting, jogging, high-impact aerobics, racquetball, tennis, strenuous wind instruments, and Valsalva maneuvers. Swimming, walking, low-impact aerobics, stationary bikes, hand bikes, and low-impact endurance exercises are recommended.4 Patients should have an eye exam every one to two months to comply with the American Diabetes Association’s Clinical Practice Recommendations.

• Diabetic nephropathy: Diabetic nephropathy is an added risk factor and indicator of CVD. Specific exercise recommendations are still to come for patients with initial diabetic nephropathy (microalbuminuria above 20 milligrams per minute) or obvious diabetic nephropathy (above 200 milligrams per minute). Patients who have protein in their urine should undergo a cardiovascular assessment and shun strenuous, high-intensity exercise programs. Since there is no good evidence indicating that individuals with diabetic nephropathy should not exercise, low- to moderate-intensity activity is recommended until further research is available.4,5

• Peripheral diabetic neuropathy: Although peripheral diabetic neuropathy presents numerous problems, physical activity can help keep nerves in the feet healthy. An appropriate exercise regimen ensures that a patient is taking adequate precautionary measures. The use of gel or air insoles and polyester or cotton polyester diabetic socks is recommended to prevent injuries and keep the feet dry. Proper footwear is essential; patients should be encouraged to consult a podiatrist to ensure suitable foot protection.

Patients must exercise caution during weight-bearing routines since peripheral diabetic neuropathy causes a loss of protective sensation in the extremities. Excessive repetitive motion can cause insensitive feet to asymptomatically blister, ulcerate, and fracture. Patients should monitor for signs of foot damage before and after exercising. To avoid injury, limit weight-bearing and highly repetitious exercises such as running, prolonged walking, and step exercises. Swimming, bike riding, rowing machines, armchair exercises, resistance bands, and other non–weight-bearing exercises are recommended.4,5,9

• Autonomic diabetic neuropathy: The presence of autonomic diabetic neuropathy may limit the patient’s exercise capacity and increase the risks of experiencing cardiovascular complications. Cardiovascular autonomic neuropathy may be diagnosed by tachycardia (above 100 beats per minute) at rest, orthostatic hypotension (drop in systolic pressure of more than 20 millimeters of mercury upon standing), or other disruptions of the autonomic nervous system involving the skin, gastrointestinal tract, pupils, or genitourinary systems.

Due to the damage that diabetes can wreak on the autonomic nervous system, hypotension and hypertension are more likely to appear at the beginning of exercise in patients with autonomic diabetic neuropathy. These individuals may also have difficulty regulating body temperature and should be cautious or avoid exercise in extremely hot or cold climates.5

• Diabetic gastroparesis: Diabetic gastroparesis is a form of autonomic diabetic neuropathy and makes gastric function unpredictable. It can be mild or severe and cause a premature feeling of satiety associated with anorexia, abdominal swelling, stomach discomfort, nausea, gastroesophageal reflux disease, and regurgitation. These symptoms can create problems with blood glucose management and ultimately cause malnutrition.
 
Patients with diabetes must juggle nutrition, insulin, oral medications, and exercise to achieve optimal blood sugar levels as diabetic gastroparesis significantly complicates treatment. The gut may perform properly, fail to function, or operate slowly. Because of rapid and sustained satiety, meals may be missed and medications skipped. The usual dose of insulin may cause hypoglycemia if the meal is slowly absorbed into the bloodstream while insulin peaks.9,10

Blood Glucose Control
Exercise can cause vast fluctuations in blood glucose, so levels must be checked before, during, and after exercise. Hypoglycemia can cause sweating, dizziness, uncontrolled shaking, confusion, and loss of consciousness during or several hours following exercise, depending on several factors. Patients experiencing these symptoms should monitor blood glucose levels before consuming carbohydrates.

If blood glucose levels dip below 100 milligrams per deciliter before or during exercise, recommend a small snack that contains 15 grams of low-glycemic carbohydrates, 7 to 10 grams of lean protein, and 5 grams of unsaturated fat. The prescribed snack will provide a long, slow, steady release of glucose during exercise.4,10 Also, patients should not begin to exercise if their blood glucose is below 100 milligrams per deciliter unless they possess tight glucose control and are cognizant of the potential effects and risks.
 
If a patient experiences two hypoglycemic episodes during one week while following the prescribed meal plan, an adjustment in medication may be necessary. The current medication protocol and nutrition program should be thoroughly evaluated before contacting the physician, as hypoglycemia can be related to patient error. Discuss any suggested alterations in medication dosage with the healthcare team.

Blood glucose levels can usually be managed with about six properly designed, low-glycemic load meals and/or snacks as prescribed by an RD or a CDE. A patient’s medication will need to be adjusted as he or she becomes more fit, gains lean body mass, and/or loses excess adipose tissue. Medication doses should be reduced when appropriate; otherwise, patients will be “feeding the medication” and gain undesired weight. Weight loss and weight management are just two of the many health benefits associated with exercise.
 
Hyperglycemia is also a significant concern for individuals with diabetes. Exercise should be avoided when blood glucose is above 250 milligrams per deciliter, accompanied with ketones. The patient should wear a medical bracelet, shoe tag, or other ID during exercise to alert rescuers if the patient can’t communicate due to hyperglycemia or hypoglycemia.4,10

Warm Up, Cool Down, and Hydration
Exercise requires warm-up and cool-down periods. Warm-ups consist of five to 10 minutes of low-intensity aerobics or calisthenics to prepare the body for the increase in intensity. Following exercise, a five- to 10-minute cool down assists with gradually returning the heart and circulatory system to their resting state.
 
Adequate hydration is paramount, as dehydration falsely elevates blood glucose levels. Dehydration (more than 2% of body weight lost) negatively affects cardiovascular function and exercise performance. These effects are accentuated during warm weather.

The American College of Sports Medicine recommends drinking about 5 to 7 milliliters per kilogram of body weight several hours before activity. (Note: Seven milliliters per kilogram is equivalent to about 1 ounce for every 10 pounds of body weight.)

Drinking during exercise is essential to prevent the detrimental effects of dehydration on body temperature and exercise performance. Individuals should monitor changes in body weight during training to establish sweating rates for specific exercise and environmental conditions (see Chart 1). This allows them to develop customized fluid replacement plans to meet their specific needs.11
           
After exercise, individuals should drink 24 ounces for each pound lost to compensate for the increased urine production that goes along with the rapid intake of large volumes of fluid.11

Exercise and Type 2 Diabetes
Evidence from long-term studies indicates that regular physical activity helps prevent or delay the onset of type 2 diabetes.5 The benefits are as follows:

• Cellular and insulin sensitivity: Regular physical activity improves glycemic control and insulin sensitivity. Endogenous insulin increases the activity of glucose transport proteins to increase glucose storage. Glucose transport protein 4 (GLUT-4) is located on the surface of the muscle cells and serves as the primary isoform responsible for augmenting glucose transport in response to exercise and insulin production. Regular exercise is associated with an increase in GLUT-4 and improves insulin sensitivity by increasing cell sensitization.12

The amount of exercise recommended by the American Diabetes Association and American Heart Association improves aerobic capacity and promotes glucose uptake for the resynthesis of muscle and liver glycogen. Resistance training also improves insulin sensitivity.5 Eccentric exercises are associated with ultrastructural muscle tearing and reduce cellular sensitivity.13,14

Exercise improves hemoglobin A1c, most notably in individuals with insulin-resistant type 2 diabetes without complications; additionally, long-term exercise is beneficial for impaired glucose tolerance. Research shows follow-through is increased when professionals assign home exercises and follow-up appointments.5

• Prevention of CVD, hyperlipidemia, and hypertension: Insulin resistance is a risk factor for CVD, particularly when associated with risk factors characteristic of the metabolic syndrome: hypertension, hyperinsulinemia, abdominal obesity, and the presence of metabolic abnormalities such as hypertriglyceridemia, low high-density lipoprotein (HDL) cholesterol, and increased low-density lipoprotein cholesterol. Regular physical activity reduces insulin resistance and increases insulin sensitivity. A low-glycemic meal plan combined with exercise helps treat and manage diabetes and CVD.5

Exercise is an effective tool in reducing triglyceride-rich, very–low-density lipoproteins and modestly increases HDL cholesterol, which helps reduce the risk for CHD. A 1% increase in HDL decreases risks for CVD by 2% in males and 3% in females.5

Hyperinsulinemia and insulin resistance are associated with hypertension and activation of the sympathetic nervous system. Aerobic exercise training may reduce sympathetic outflow and decrease blood pressure by improving insulin sensitivity.5,12

• Treating and preventing obesity: Exercise enhances weight loss and weight maintenance when combined with a calorie-restricted, low-glycemic load diet. Reducing the meal plan’s glycemic load may help prevent and treat obesity, CVD, and type 2 diabetes.
 
An individual’s muscle mass plays a key role in the regulation, breakdown, and utilization of glucose, protein, and lipids. Resistance training can significantly increase muscle mass and is a promising weight-loss tool. Sodium dependent-glucose co-transporters represent a non–insulin-dependent form of glucose entry into cells and are enhanced by resistance training. It was found that a 16-week resistance training program increased muscle quality by 62%, improved insulin sensitivity by 25%, decreased free fatty acids by 13%, and lowered C-reactive protein by 20%.5,15,16

Exercise and Type 1 Diabetes
With type 1 diabetes, the pancreas’ insulin-producing beta cells are either damaged or dysfunctional due to autoimmune antibody attack. Therefore, people with type 1 diabetes must juggle exogenous insulin, exercise, and nutrition and frequently monitor blood glucose to remain within recommended guidelines.

Healthy individuals with type 1 diabetes can perform competitive and recreational sports, leisure activities, and collegiate- and professional-level sports via self-management. An example is Gary Hall, Jr, an American swimmer with type 1 diabetes who competed in the 1996, 2000, and 2004 Olympic games and won 10 medals. A patient with type 1 diabetes must be able to make adjustments to his or her therapeutic regimen to ensure safety and optimal performance.5

Hypoglycemia is a major concern and can occur during, immediately following, or several hours after exercise. The patient must be knowledgeable regarding exercise-related metabolic and hormonal shifts. Aggressive insulin regimens and therapy provide people with type 1 diabetes the flexibility and ability to control insulin doses as needed. Prior recommendations promoting exercise carbohydrates to cover calculated intensity and duration of exercise, without regard to blood glucose level, are not acceptable, as they hinder glycemic control and weight management.5

Patients with type 1 diabetes should consume a small snack if blood glucose levels are below 100 milligrams per deciliter. Patients on insulin pumps need to decrease their basal rates by 30% to 50% two hours before exercising. Patients should monitor blood glucose before, during, and after exercising to identify obligatory adjustments in insulin and nutrition.

If necessary, patients should consume rapid-acting, high-glycemic carbohydrates using the Rules of 15 (see sidebar) to avoid hypoglycemia.

Type 1 diabetes in children and adolescents with typical active lifestyles warrants special attention. A deep understanding of the complex relationship between insulin and physical activity is required of parents, teachers, and athletic coaches. The hormonal changes associated with growth and development can create challenges for blood glucose control. Nonetheless, with proper training in all aspects of exercise and diabetes self-management, exercise can be safe and rewarding for children and adolescents with type 1 diabetes.5

Middle-aged and older individuals with diabetes should be encouraged to live an active life. Aging causes atrophy of muscles (sarcopenia), ligaments, bones, and joints, and inactivity exacerbates this process. The accelerated and progressive decline in fitness, muscle mass, and strength associated with aging is preventable with a combination of aerobic and resistance training. The marked decrease in insulin sensitivity observed with advancing age is primarily due to inactivity. Studies on exercise in older adults have demonstrated remarkable outcomes, including a reduced incidence of chronic diseases and a higher quality of life.

Clearly, the increased incidence of type 2 diabetes can be largely attributed to the rising rate of obesity. In July, the Centers for Disease Control and Prevention reported that about one in four Americans is obese. Diabetes significantly reduces life span and quality of life. Our challenge is to translate and apply the knowledge we have to improve our patients’ health. Physical activity has protective properties and serves a key role in the primary prevention of diabetes and cardiovascular disease.

It is imperative for the healthcare team to promote exercise as an important component of diabetes prevention and management.

— Dino Pierce, CFT, CPT, RD, CDE, is a speaker, an author, a sports nutritionist, and the director of an outpatient diabetes education program. He has developed a systematic success program outlined in his books, audio programs, live events, and videos.

Determining Sweat Rate (Example)
Preexercise weight: 170 lb
Postexercise weight: 169 lb after one-hour run
Amount consumed during run: 16 oz
Sweat rate: 32 oz per hour
Recommendation: Individual should drink 8 oz every 15 minutes to replace sweat losses.

The Rules of 15 4,5,10
• If blood glucose is 70 milligrams per deciliter or below, consume 15 grams of fast-acting carbohydrate, enough to raise blood glucose 40 to 50 milligrams per deciliter, depending on exercise intensity, exogenous insulin levels, and insulin sensitivity.

• After consuming 15 grams of carbohydrates, wait 15 minutes and check blood glucose again. If it is still 70 milligrams per deciliter or less, repeat the process.

• When blood glucose is above 100 to 110 milligrams per deciliter, no further action is needed. Resume exercise with caution and continue to check blood glucose every 15 to 30 minutes.

• Check blood glucose one hour following an exercise session, ensuring that blood glucose stays above 70 milligrams per deciliter, as residual insulin and intensified insulin sensitivity may continue to drop blood glucose at accelerated rates.

• When an incident occurs, document it to prevent future events. Because hypoglycemia is common, high-glycemic carbohydrates should be readily available at all times.

Learning Objectives
After completing this article and examination, the reader will be able to:

1. List at least three exercises recommended by the American Diabetes Association and American Heart Association for individuals with type 2 diabetes.

2. Discuss which patients are considered high risk for cardiovascular disease and require a stress test prior to beginning an exercise program.

3. Explain how regular physical activity improves glycemic control and insulin sensitivity via sodium dependent-glucose co-transporters and glucose transport proteins.

4. Calculate hydration needs both preexercise and postexercise according to the American College of Sports Medicine.

5. Recommend appropriate snacks and treatment methods for maintaining recommended blood glucose levels.

6. Discuss the differences between nonproliferative diabetic retinopathy and proliferative diabetic retinopathy and exercise recommendations.

References
1. McGinnis JM. Diabetes and physical activity: Translating evidence into action. Am J Prevent Med. 2002;22(4S):1-2.

2. Buse JB, Ginsberg HN, Bakris GL, et al. Primary prevention of cardiovascular diseases in people with diabetes mellitus: A scientific statement from the American Heart Association and the American Diabetes Association. Circulation. 2007;115:114-126.

3. Sigal RJ, Kenny GP, Wasserman DH, Castane da-Sceppa C, White RD. Physical activity/exercise and type 2 diabetes: A consensus statement from the American Diabetes Association. Diabetes Care. 2006;29(6):1433-1438.

4. American Diabetes Association. Position statement: Diabetes mellitus and exercise. Diabetes Care. 2002;25:S64.

5. Devlin JT, Ruderman N. Diabetes and exercise: The risk-benefit profile. In: The Health Professional’s Guide to Diabetes and Exercise. American Diabetes Association; 1995.

6. Pendergrass M, Lynch CC, Myers E, Blake S. Exercise and diabetes. The University of Louisiana at Monroe School of Pharmacy Diabetes Series. 2004.

7. Medline Plus Medical Encyclopedia. Diabetic retinopathy. Available at: http://www.nlm.nih.gov/medlineplus/ency/article/001212.htm. Accessed March 6, 2007.

8. Nason ET. Valsalva’s maneuver. Rehabworks. Available at: http://rehabworks.ksc.nasa.gov/education/topics/valsalva.php. Accessed March 6, 2007.

9. American Diabetes Association. Gastroparesis and diabetes. Available at: http://www.diabetes.org/type-2-diabetes/Gastroparesis.jsp. Accessed March 6, 2007.

10. Pereira MA, Swain J, Goldfine AB, Rifai N, Ludwig DS. Effects of a low-glycemic load diet on resting energy expenditure and heart disease risk factors during weight loss. JAMA. 2004;292(20):2482-2490.

11. Sawka MN, Burke LM, Eichner ER, et al. American College of Sports Medicine. Position stand: Exercise and fluid replacement. Med Sci Sports Exerc. 2007;377-390.

12. O’Reily KP, Warhol MJ, Fielding RA, et al. Eccentric exercise-induced muscle damage impairs muscle glycogen repletion. J Appl Physiol. 1987;63(1),252-256.

13. Costill DL, Pascoe DD, Fink WJ, et al. Impaired muscle glycogen resynthesis after eccentric exercise. J Appl Physiol. 1990;69(1), 46-50.

14. Castaneda F, Layne J, Castaneda C. Skeletal muscle sodium glucose co-transporters in older adults with type 2 diabetes undergoing resistance training. Int J Med Sci. 2006;3(3):84-91.

15. Brooks NE, Layne JE, Gordon PL, et al. Strength training improves muscle quality and insulin sensitivity in Hispanic older adults with type 2 diabetes. Int J Med Sci. 2006;4(1):19-27.

16. U.S. Department of Health and Human Services. Physical activity and health: A report of the surgeon general. Washington, D.C.: Centers for Disease Control and Prevention; 1996.

Examination
1. Following a thorough assessment, you should advise a patient who has not been physically active to embark on an exercise program utilizing leisurely activities such as:
a. aerobic exercise for 20 minutes at least four times per week.
b. weight machines and/or free weight work to build lean body tissue.
c. walking, doing yard work, swimming, and dancing.
d. power lifting, bodybuilding, and strong man training.
 
2. Exercise-induced hypoglycemia can occur in individuals with type 1 and type 2 diabetes for which of the following reasons:
a. Exercise increases insulin sensitivity and glucose uptake in the muscles.
b. Exercise interferes with the production of the glucose-raising hormones (eg, catecoholamines and glucagon).
c. Exercise burns up calories, decreasing blood sugar.
d. Exercise increases insulin production.

3. A patient can be considered at high risk for cardiovascular disease and require a stress test if he or she exhibits which of the following:
a. Has been diagnosed with type 1 diabetes for longer than 10 years and does not have microvascular disease
b. Walks 30 minutes per day three to six days per week
c. Is older than 35, has been diagnosed with type 2 diabetes for longer than 10 years, and has autonomic neuropathy
d. Lacks risk factors for coronary artery disease and peripheral vascular disease

4. Which of the following statements is true about exercise and nonproliferative diabetic retinopathy:
a. The degree of retinopathy determines the types of activities and exercises that are safe.
b. Individuals with nonproliferative diabetic retinopathy do not have any exercise restriction.
c. With the exception of a Valsalva maneuver, all other activities and exercises are acceptable.
d. An eye exam is only necessary before exercise begins.

5. Specific exercise recommendations for patients with microalbuminuria above 20 milligrams per minute include:
a. weight lifting, power lifting, and bodybuilding.
b. speed walking, step aerobics, and dance aerobics.
c. spinning, elliptical exercise machines, and water aerobics.
d. Currently, exercise recommendations do not exist.

6. Some individuals with diabetes must manage nutrition, insulin, oral medications, and exercise in an attempt to achieve optimal blood sugar levels. The risk or presence of which of the following complicates the equation:
a. Low-glycemic meal planning
b. Gastroparesis
c. Autonomic diabetic neuropathy
d. b and c

7. If a patient’s blood glucose levels dip to 100 milligrams per deciliter before or during exercise, you should:
a. recommend consuming 15 grams of rapid-acting carbohydrates immediately, followed by 12 to 15 grams of lean protein and 9 grams of saturated fat within one-half hour.
b. recommend consuming 15 grams of low-glycemic carbohydrates, 7 to 10 grams of lean protein, and 5 grams of unsaturated fat. For the cognizant patient with tight control, no action is necessary other than continued monitoring.
c. recommend review of medications by the physician or diabetes educator.
d. caution the patient that he or she is putting himself or herself at risk by overexercising.
 
8. Optimal hydration is achieved by:
a. drinking 5 to 7 milliliters per kilogram body weight several hours before exercise.
b. determining sweat rate to develop individualized fluid replacement needs during exercise.
c. drinking 24 ounces per pound of body weight lost during exercise.
d. All of the above
 
9. Glucose transport proteins are responsible for which of the following:
a. A non–insulin-dependent mechanism for glucose entry into cells
b. Ideal weight-loss supplements for patients with diabetes
c. Proteins that primarily transport albumin to the liver
d. Proteins that increase blood pressure

10. Healthy patients with type 1 diabetes should not be involved in competitive sports at the college or professional level because of the extreme exertion and endurance necessary.
a. True
b. False