Physiological aging process &role of exercise

1. Physiological aging process &role of exercise Dr_R.heidarimoghadam (MD&PhD) Exercise physiologist

2. DEFINITION OF AGING • Old and aging depends on the age and experience of the speaker. • Chronological age - number of years lived • Physiologic age - age by body function • Functional age - ability to contribute to society

3. CHRONOLOGICAL CATEGORIES • Young-Old - (ages 65 - 74) • Middle-Old - (ages 75 - 84) • Old-Old - (age 85 and older)

4. PHYSIOLOGICAL THEORIES OF AGING What causes the body to age?

5. PROGRAM THEORY Cells replicate a specific number of times and then die. Happens again, and again in lab experiments.

6. ERROR THEORY • The structure of DNA is altered as people age • Due to alterations, DNA not read correctly • Results in transcription and translation malfunction • Results in aging/illness/ cancer directly, or indirectly

7. CELLULAR THEORY Normal wear and tear causes cells to function improperly

8. FREE RADICAL THEORY • Lipids in cell membranes are exposed to radiation or free radicals • Cell membrane ruptures and cell dies • In test tubes this actually occurs

9. NUTRITIONAL MODEL THEORY • If animal fed 50-60% less than it eats on its own - lives longer • Assumption: Lean mass, as opposed to adipose tissue results in greater health

10. COLLAGEN THEORY OF AGING As we age, collagen in body ages also. Causes hypertension and other organ malfunctions

11. MUTATING AUTO-IMMUNE THEORY • Cells have normal functions - secrete normal proteins • As cells age - mutate and secretions viewed as foreign by body • Solicits immune response • Shuts cell down • Cause biological errors and entire organ malfunctions

12. NEURO-AGING THEORY • All cells undergo nervous system degeneration • Results in changes in hormonal release • Leads to decline in cell function

13. NONE OF THESE THEORIES TOTALLY ACCEPTED Scientists hypothesize it might be combination of several or all

14. PHYSIOLOGICAL AGING OF THE HUMAN BODY BY SYSTEMS

15. RESPIRATORY SYSTEM • Lungs become more rigid • Pulmonary function decreases • Number and size of alveoli decreases • Vital capacity declines • Reduction in respiratory fluid • Bony changes in chest cavity

16. CARDIOVASCULAR SYSTEM • Heart smaller and less elastic with age • By age 70 cardiac output reduced 70% • Heart valves become sclerotic • Heart muscle more irritable • More arrhythmias • Arteries more rigid • Veins dilate

17. REPRODUCTIVE SYSTEM Male: • Reduced testosterone level • Testes atrophy and soften • Decrease in sperm production • Seminal fluid decreases and more viscous • Erections take more time • Refractory period after ejaculation may lengthen to days

18. REPRODUCTIVE SYSTEM Female: • Declining estrogen and progesterone levels • Ovulation ceases • Introitus constricts and loses elasticity • Vagina atrophies - shorter and drier • Uterus shrinks • Breasts pendulous and lose elasticity

19. NEUROLOGICAL SYSTEM • Neurons of central and peripheral nervous system degenerate • Nerve transmission slows • Hypothalamus less effective in regulating body temperature • Reduced REM sleep, decreased deep sleep • After 50% lose 1% of neurons each year

20. MUSCULOSCELETAL SYSTEM • Adipose tissue increases with age • Lean body mass decreases • Bone mineral content diminished • Decrease in height from narrow vertebral spaces • Less resilient connective tissue • Synovial fluid more viscous • May have exaggerated curvature of spine

21. Exercise and Aging

22. Goals • Develop an understanding of normal aging physiology • Incorporate aerobic and resistance exercise into treatment and prevention plans of the elderly • Appropriate pre-exercise assessment

24. Exercise and aging physiology

25. Physiologic changes with aging (Board Questions) • Decreased • Muscle mass • Muscle strength • Muscle power • Muscle endurance • Muscle contraction velocity • Muscle mitochondrial function • Muscle oxidative enzyme capacity

26. Decreased Maximal and submaximal aerobic capacity Cardiac contractility Maximal heart rate Stroke volume and cardiac output Nerve conduction velocity Balance Decreased Proprioception Gait velocity Gait stability Insulin sensitivity Glucose tolerance Immune function Bone mass/strength/density Collagen cross-linkage, thinning cartilage, tissue elasticity Physiologic changes with aging (Board Questions)

27. Physiologic Questions • Increased • Arterial stiffness • Myocardial stiffness • Systolic blood pressure • Diastolic blood pressure • Visceral fat mass • Total body fat • Intramuscular lipid accumulation

28. Use It or Lose It • Sedentary people lose large amounts of muscle mass (20-40%) • 6% per decade loss of Lean Body Mass (LBM) • Aerobic activity not sufficient to stop this loss • Only resistance training can overcome this loss of mass and strength • Balance and flexibility training contributes to exercise capacity

29. What is exercise? • Lifestyle choices • Organized sports • Unstructured play • Household and Occupational tasks

30. Increased Muscle Mass • Endurance training emphasis • Walking isn’t enough • Progressive resistance training • DM prevention? • Dependency prevention? • Falls and fractures • Disuse • Sarcopenia • Frailty

31. Use It and Lose Less of It • Resistance training improves strength by a range of 40-150% • Lean body mass increases 1-3 kg • Muscle fiber area 10-30%

32. Body composition • Genetic, lifestyle and disease factors • Metabolic, cardiovascular and musculoskeletal systems impacted • Lifestyle is under patient’s control • Weight manangement

33. Burning Fat • Decreases in total body adipose tissue • Aerobic and resistive training • Energy restricted diets and/or high volume exercise (5-7 hours/week) • Visceral fat selectively mobilized

34. Metabolic syndrome Vascular disease Osteoarthritis Gallbladder disease Diabetes Hypertension Dyslipidemia Sleep apnea Breast cancer Colon cancer Endometrial cancer Impotence Osteoarthritis Depression Disability What’s fat got to do with it?

35. Exercise and prevention

36. Diabetes and Osteoporosis • Insulin Resistance • Improves insulin sensitivity • Detraining may reduce exercise effect • Primary prevention demonstrated • Osteoporosis prevention and treatment • Stabilization or increase in bone density in pre- and postmenopausal women with resistive or weight bearing exercise • 1-2% per year difference from controls

37. Dyslipidemia • Not a lot of data in elderly • No clear primary and secondary prevention data • Exercise associated with less atherogenic profiles • Duration and frequency factors • Weight loss (or fat loss) associated with increased HDL • Gender differences with training • Less training effect on HDL in women

38. Hypertension • Most trials cross sectional and cohort • Lower pressures in active individuals • 5-10 mmHg • Type and intensity • Greater training effect in those with mild to moderate hypertension • 6-7 mmHg drop in systolic and diastolic pressure • Effect present in low-to-moderate exercise

39. CVD • Exercise training beneficial in CVD • Reduced claudication pain • Greater walking distance • Improved functional endpoints • Benefit in selected patients with coronary artery disease.

40. Arthritis • Improved functional status • Faster gait • Lower depression • Less pain • Less medication use • Strength and endurance training benefit

41. Cancer • Potential protective benefits with • Breast Cancer • Colon Cancer • Prostat

42. Exercise treatment of chronic disease • May treat symptoms and disuse and not the underlying disease • Parkinson’s • COPD • Claudication • Chronic renal failure • May reduce recurrence of disease • CVD • Falls

43. Exercise and emotional health and well being

44. Emotional well being • Genetic, social, personality, and psychological constructs • Leading cause of death and disability in developed countries

45. Exercise and Mental Health • Positive psychologic attributes • Lower prevalence and incidence of depressive symptoms • Reversal of hippocampal volume loss? • Reversal of cognitive loss? • 14 randomized, controlled trials: • Aerobic and resistance training • Higher intensities • Meaningful improvements in depression • Response rates of 31-88% • Equipotent to standard treatment

46. Exercise and disability

47. Function relates to strength • Non-linear relationship between strength and function • Concept of Threshold • EPESE Study: • Physically active patients at baseline less likely to develop disability • Exercise improves functional limitations • Functional balance tasks • Gait speed • Arthritis

48. Exercise and longevity

50. Exercise Evaluation