Chapter 17 Exercise for Special Populations

1. Chapter 17Exercise for Special Populations EXERCISE PHYSIOLOGY Theory and Application to Fitness and Performance, 6th edition Scott K. Powers & Edward T. Howley Presentation revised and updated by Brian B. Parr, Ph.D. University of South Carolina Aiken

2. Diabetes • Characterized by an absolute (type 1) or relative (type 2) insulin deficiency that results in hyperglycemia • A major health problem and leading cause of death in the United States • More than 18.2 million have diabetes • Only 11.1 million are diagnosed • Warning signs: • Frequent urination/unusual thirst • Extreme hunger • Rapid weight loss, weakness, and fatigue • Irritability, nausea, and vomiting

3. Diabetes • Type 1 • Lack of insulin • Dependent on exogenous insulin • Develops early in life • Associated with viral infections • 5–10% diabetic population • Type 2 • Resistance to insulin • Develops later in life • Associated with upper-body obesity • 90–95% diabetic population

4. Characteristics of Type 1 and Type 2 Diabetes Table 17.1

5. Exercise and the Diabetic • Control of blood glucose is important • Adequate insulin is required • Ketosis • Metabolic acidosis from accumulation of ketone bodies • May result from a lack of insulin

6. Effect of Prolonged Exercise in Diabetics Figure 17.1

7. Exercise and Type 1 Diabetes • Metabolic control before physical activity • Avoid exercise if fasting glucose is >300 mg/dl (or >250 mg/dl with ketosis) • Ingest carbohydrates if glucose is <100 mg/dl • Blood glucose monitoring before and after exercise • Identify when changes in insulin or food intake is needed • Learn how blood glucose responds to different types of exercise • Food intake • Consume carbohydrates to prevent hypoglycemia • Carbohydrates should be readily available during and after exercise

8. Effect of Plasma Insulin Levels in Type 1 Diabetics During Exercise Figure 17.2

9. Exercise Prescription for Type 1 Diabetes • Exercise 20–60 min, 3–4 days per week, 50–85% heart rate reserve • May use non-weight bearing, low-impact activities • If weight-bearing activities are contraindicated • Use lighter weights (40–60% 1RM), 15–20 reps • Avoid the Valsalva maneuver • Heavier weights for athletes • Drink extra fluids and have carbohydrates available • Exercise with someone in case of emergency

10. Exercise and Type 2 Diabetes • Exercise is a primary treatment • Help treat obesity • Help control blood glucose • Combination of diet and exercise may eliminate need for drug treatment • Exercise prescription • Dynamic aerobic activity at 50–90% HRmax • 20–60 min, 4–7 times/week • Strength training is also recommended • Goal to expend a minimum of 1,000 kcal/week • May need to reduce dosage of medications to maintain blood glucose

11. American Diabetes Association Goals for Nutrition Therapy • Attain and maintain optimum metabolic outcomes to reduce risk of complications • Blood glucose in normal range • Improved lipid and lipoprotein profile • Lower blood pressure • Prevent and treat chronic diabetes complications • Improve health through healthy food choices and physical activity • Address individual nutritional needs

12. Prevention or Delay of Type 2 Diabetes • Impaired fasting glucose (IFG) • Fasting BG 100–125 mg/dl • Impaired glucose tolerance (IGT) • Oral glucose tolerance test • 2-hour blood glucose 140–199 mg/dl • Prediabetes • Having IFG or IGT • Likely to develop type 2 diabetes • 150 min/week of physical activity and losing 5-10% of body weight reduces risk • Better approach than using drugs

13. Asthma • A respiratory problem characterized by a shortness of breath accompanied by a wheezing sound • Due to: • Contraction of smooth muscle of airways • Swelling of mucosal cells • Hypersecretion of mucus • 20 million are affected by asthma • 1.9 million emergency room visits • 4,000 deaths • Direct and indirect costs of $16.1 billion

14. Asthma: Diagnosis and Causes • Diagnosed using pulmonary-function testing • Low maximal expiratory flow rate • Triggers • Dust, chemicals, antibodies, exercise • Causes influx of Ca+2 into mast cells • Release of chemical mediators that cause: • Increased smooth muscle contraction leading to bronchoconstriction • Bronchoconstrictor reflex via vagus nerve • Inflammatory response

15. Proposed Mechanism by Which an Asthma Attack Is Initiated Figure 17.3

16. Prevention and Relief of Asthma • Prevention • Avoidance of allergens • Immunotherapy • Medications • Cromolyn sodium • 2-agonists • Theophylline • Corticosteroids • Leukotriene inhibitors

17. Exercise-Induced Asthma • More common in asthmatics • Does not necessarily impair performance if controlled • Caused by drying of respiratory tract • Increases osmolarity on surface of mast cell • Triggers Ca+2 influx and airway narrowing • Reducing the chance of an attack • Warm-up • Short-duration exercise • Treatment • -agonist in case of attack during exercise • Other medications to prevent attack

18. Chronic Obstructive Pulmonary Disease (COPD) • Includes chronic bronchitis, emphysema, and bronchial asthma • Can create irreversible changes in the lung • Can severely limit normal activities • Testing for COPD • FEV1 • Graded exercise test • VO2max • Maximal exercise ventilation • Changes in arterial PO2 and PCO2

19. Treatment of COPD • Goals: • Reduced reliance on O2 and medications • Improved ability to complete daily activities • Treatments: • Medications (including supplemental O2) • Breathing exercises • Dietary therapy • Exercise • Counseling • Outcomes: • Increased exercise tolerance without dyspnea • Increased sense of well-being

20. Hypertension • Classifications: • Normal <120/<80 mmHg • Prehypertension 120–139/80–89 mmHg • Hypertension (stage I) 140–159/90–99 mmHg • Recommendations • Lose weight if overweight • Limit alcohol intake • Reduce sodium intake • Maintain adequate dietary K+, Ca+2, Mg+2 • Stop smoking • Reduce dietary fat, saturated fat, and cholesterol intake

21. Exercise for Hypertension • Exercise can be used as a non-drug treatment • Recommendations: • Moderate intensity exercise (40–60% HR reserve) • 30 minutes on most, preferably all, days • Goal of expending 700–2000 kcal/week • ACSM recommendation for improving VO2max can also be followed • Precautions • Blood pressure should be monitored for those on medications

22. Cardiac Rehabilitation: Patient Population • Those who have or have had: • Angina pectoris • Chest pain due to ischemia • Myocardial infarction (MI) • Heart damage due to coronary artery occlusion • Coronary artery bypass graft surgery (CABGS) • Bypass one or more blocked coronary arteries saphenous vein or internal mammary artery • Angioplasty (PTCA) • Balloon tipped catheter used to open occluded arteries • May insert a stent to keep artery open

23. Cardiac Rehabilitation: Medications • b-blockers • Reduce work of the heart • Anti-arrhythmics • Control dangerous heart rhythms • Nitroglycerine • Reduce angina symptoms

24. Cardiac Rehabilitation: Testing • Graded exercise testing • ECG monitoring (12-lead) • Heart rate and rhythm • Signs of ischemia (ST segment depression) • Blood pressure • Rating of perceived exertion (RPE) • Signs or symptoms • Chest pain • May include radionuclide imaging • Evaluate perfusion (201Thallium) • Evaluate ventricular ejection (99Technetium)

25. Cardiac Rehabilitation: Exercise Programs • Exercise prescription • Based on GXT results • MET level, heart rate, signs/symptoms • Whole body, dynamic exercise • Intensity, duration, and frequency based on severity of disease • Effects • Increased functional capacity (VO2max) • Reduced signs/symptoms of ischemia • Improved risk factor profile

26. Exercise For Older Adults • VO2max declines ~1% per year • Regular exercise may reduce rate of decline • Benefits of participation • Improved risk factor profile • Increased strength and VO2max • Increased bone mass • Recommendations • Similar to younger subjects • Medical exam and risk factor screening is essential

27. Exercise and Bone Health • Osteoporosis results in reduced bone mineral density and increased fracture risk • More common in women over fifty due to lack of estrogen • Prevention and treatment • Dietary calcium • >1000 mg/day through food and supplements • Hormone replacement therapy (HRT) • Prevents bone loss and reduces fracture risk • May increase risk of cardiovascular disease and cancers • Exercise • Weight-bearing activities and resistance training • 2–3 hours per week

28. Exercise During Pregnancy • Regular endurance exercise poses no risk to the fetus and is beneficial for the mother • Recommendations • Pregnant women should consult their physician prior to beginning any exercise program • Absolute and relative contraindications • Follow ACSM/CDC recommendation • 30 min/day of moderate-intensity activity on most, preferably all, days • Intensity determined by: • Heart rate, Rating of perceived exertion, or “talk test” • No supine exercise after first trimester