Exercise, Successful Aging, and Disease Prevention

1. Exercise, Successful Aging, and Disease Prevention Chapter 17

2. Objectives • Describe what the term “healthspan” means • Explain the concept of successful aging compared to traditional views of the aging process • Explain the basis of the Physical Activity Pyramid • Answer the question: “How safe is exercise?” • Describe the goals of Healthy People 2010 • What is SEDS, and why is it important?

3. Objectives (cont’d) • List important age-related changes in: (1) muscular strength, (2) joint flexibility, (3) nervous system function, (4) cardiovascular function, (5) pulmonary function, and (6) endocrine function and body composition • Describe five field tests to assess flexibility of major body areas • Describe research showing regular physical activity protects against disease and may even extend life

4. Objectives (cont’d) • List the three major causes of death in the United States • List and describe the four major coronary heart disease risk factors • List secondary and novel risk factors for coronary heart disease • List specific components of the blood lipid profile, and give values considered desirable for each • Discuss factors that affect cholesterol lipoprotein levels

5. Objectives (cont’d) • Explain how regular physical activity reduces coronary heart disease risk • Describe the occurrence of CHD risk factors in children • Explain interactions between CHD risk factors

6. The Graying of America • Elderly persons make up the fastest growing segment of America • ~35 million Americans exceed age 65 • By the year 2030, 70 million Americans will exceed age 85

11. Successful Aging • Requires maintenance of enhanced: • Physiologic function • Physical fitness • Components of successful aging • Physical health • Spirituality • Emotional and educational health • Social satisfaction

12. Physical Activity and Aging • Physical activity attenuates the impact that “normal aging” has on: • Blood pressure • Body composition • Insulin sensitivity • Bone mass

13. Healthspan • The total number of years a person remains in excellent health

14. Healthy Life Expectancy • The expected number of years a person might live in the equivalent of full health • Disability-adjusted life expectancy • Considers the years of ill health, weighted according to severity and subtracted from expected overall life expectancy to compute the equivalent years of healthy life

16. Years of Life Lost (YLL) • Most prominent factors responsible for decreased life expectancy in non-Western countries include: • Low birth weight • Vitamin/mineral deficiency • Unsafe water/sanitation procedures • Unsafe sex – HIV • Introduction of carcinogens • Work-related risk

17. Years of Life Lost (YLL) (cont’d) • Most prominent factors responsible for decreased life expectancy in Western countries include: • Tobacco use • High blood pressure • Increased cholesterol • Obesity • Low levels of physical activity • Low levels of fruit and vegetable consumption

18. Physical Activity Participation • Only 15% of Americans engage in regular vigorous physical activity • >60% of Americans do not engage in any regular physical activity • 25% of Americans lead sedentary lives • Participation in fitness activity declines with age

20. Healthy People 2010 • Primary aims • Increase quality and years of healthy life • Eliminate health disparities among the nation’s citizens

21. Exercise and Sudden Death • Heavy physical exertion poses a small risk of sudden death during the activity • ~1 sudden death per 1.5 million exercise episodes of exertion • However, the longer term reduction in overall death risk from regular physical exercise outweighs the small potential for acute cardiovascular complications

22. Sedentary Environmental Death Syndrome (SeDS) • Physical inactivity produces a constellation of problems and conditions that lead to premature death • The term Sedentary environmental Death Syndrome, coined by Frank Booth, identifies this deleterious condition • http://hac.missouri.edu

23. Sedentary Environmental Death Syndrome (SeDS) (cont’d) • SeDS will cause 2.5 million Americans to die prematurely in the next decade • SeDS will cost $2 to $3 trillion in health expenses in the United States in the next decade • SeDS is related to 23 medically related conditions: e.g., obesity, high blood pressure, insulin resistance

25. Aging and Muscular Strength • Men and women achieve maximum strength between the ages of 20 and 30 years • Thereafter, strength progressively declines for most muscle groups • By age 70, overall strength decreases by ~30%

26. Sarcopenia • Refers to a decrease in muscle mass associated with aging

27. Muscle Trainability Among the Elderly • Regular exercise training retains body protein and blunts the loss of muscle mass and strength with aging

29. Aging and Joint Flexibility • With advancing age, connective tissue becomes stiffer and more rigid, which reduces joint flexibility • Regularly moving joints through their full range of motion increases flexibility by 20 to 50%

30. Aging and Endocrine Changes • Endocrine function changes with age, particularly the pituitary, pancreas, adrenal, and thyroid glands

31. Impaired Glucose Metabolism • Factors contributing to age-associated impairments in glucose metabolism include: • Insulin resistance • Relative insulin deficiency • Combined effect of insulin resistance and relative insulin deficiency

32. Aging and Thyroid Dysfunction • Thyroid dysfunction commonly occurs in the elderly as a result of: • Lowered pituitary gland secretion of thyroid-stimulating hormone • Reduced output of thyroxine by the thyroid gland

34. Aging and the Hypothalamic-Pituitary-Gonadal Axis • Aging is associated with altering interactions between hypothalamic releasing hormones and the anterior pituitary gland and gonads • Menopause and andropause reflect the gender-specific manifestations of these altered interactions

35. Adrenal Cortex • Adrenopause • Refers to the significant decrease in output of dehydroepiandrosterone (DHEA) and its sulfated ester (DHEAS) from the adrenal cortex • DHEA declines progressively after the age of 30

36. Growth Hormone/Insulin-Like Growth Factor 1 Axis • Somatopause • Refers to the age-associated reduction in mean pulse amplitude, duration, and fraction of secreted growth hormone (GH) • A concomitant decrease in circulating insulin-like growth factor (IGF) 1 also occurs

37. Aging and Nervous System Function • Aging per se is associated with • 37% decline in the number of spinal axons • 10% decline in nerve conduction velocity • Impairments in neuromuscular performance • Regular physical activity may attenuate the age-associated declines in neuromuscular performance

38. Aging and Pulmonary Function • Aging per se is associated with • A decline in pulmonary function • Regular physical activity may attenuate the age-associated declines in pulmonary function

39. Aging and Cardiovascular Function • Maximal oxygen uptake ( O2max) declines steadily after the age of 20 • A slower rate of decline occurs for individuals who maintain an active lifestyle that includes regular aerobic exercise training • Physical activity, however, does not entirely offset aging’s effect on O2max

41. Aging and Cardiovascular Function (cont’d) • Skeletal muscle oxidative capacity and capillarization remain similar in older and younger individuals with comparable training history • Thus, age-associated reduction in cardiac output represents the most likely explanation for the decrease in O2max per kg of active muscle that accompanies aging

44. Aging Response to Exercise Training • For the healthy elderly, exercise training enhances the heart’s capacity to pump blood and increases aerobic capacity to the same degree as in younger adults

45. Aging and Body Composition • Aging per se is associated with: • A decline in fat-free mass (FFM) • An increase in fat mass (FM) • A preferential deposition of fat into the abdominal visceral fat depot • Regular physical activity may attenuate the age-associated decline in FFM, while depressing the age-associated increase in FM

49. Benefits of Regular Exercise • Regular physical activity and exercise attenuates the risks associated with: • Smoking • Obesity • Diabetes • Hypertension • Coronary heart disease