1. 1 Aging and Exercise Brooks Chpt 32 Brooks Chpt 19 Rogers and Evans

2. 2 Aging and Exercise  It is dificult to quantify the effects of aging on physiological function and physical performance.  Some people physically deteriorate with age due to a lack of exercise, obesity, poor diet, smoking, and stress.  Some individuals are active and are still fit in their 50s, 60s and 70s.

3. 3 Aging and Exercise  Disease further complicates our understanding of the aging process.  osteoarthritis, atherosclerosis  Physiological systems vary in the extent to which they deteriorate with age.  It is difficult to separate deconditioning and disease from the aging process.

4. 4 Aging and Exercise  Lifestyle (diet, exercise) will influence performance and health during aging, but they will not halt the aging process.  Life expectancy in 1900: 47 years 2000: 76 years  The maximum lifespan (100) has not changed  Quality of life is very important. North Americans only have healthy quality life during 85% of their lifespan.

5. 5 Response to Training  Older people readily adapt and respond to endurance and strength training.  Endurance training helps maintain cardiovascular function, enhances exercise capacity, and reduces factors associated with heart disease, diabetes, some cancers.  Strength training prevents loss of muscle mass and strength with aging.

6. 6 Response to Training  Exercise prevents bone loss and improves postural stability, which  the risk of fractures and falling.  Mobility exercises improve flexibility and joint health.  Exercise also provides psychological benefits.  Exercise does not retard the aging process, it just allows the person to perform at a higher level.

7. 7 The Aging Process  Physiological control mechanisms are impaired in older people.  reaction time  resistance to disease  work capacity  recovery time  body structures are less capable and resilient  Very fit older individuals are still prey to the ravages of old age.

8. 8 The Aging Process  Genetic factors have a profound influence on the length of life, while environmental and genetic factors govern quality of life.  Life spans of identical twins are remarkably similar (2 - 4 yrs of each other).  nonidentical twins (7 - 9 yrs)

9. 9 The Aging Process  Peak physiological function occurs at about 30 years of age.  After 30, most physiological factors decline at a rate of 0.75 to 1.0% a year.   VO 2 max, CO, strength, power, flexibility   neural function,  body fat  table 32-2; physiological effects of aging  All of these factors can be positively affected by exercise, especially if training has been maintained throughout life.

10. 10 Maximal Oxygen Consumption  VO 2 max  approx 30% between 20 and 65  rate of decline is greatest after age 40  decreases in VO 2 max is quite variable   VO 2 max due to  ’s in HR max, SV, power output, fat-free mass, a-vO 2 difference.

11. 11 Heart Rate  During submax exercise, HR is lower with age at any relative exercise intensity, but the same at any absolute intensity.  Cardiovascular drift is greater with age.  Longer recovery rate following exercise.   -adrenergic responsiveness  with age, this will  HR max.  Age related  in HR max is partially due to deconditioning and loss of muscle mass.

12. 12 Stroke Volume and Cardiac Output  Aging impairs the heart’s capacity to pump blood.  CO and SV is  in older adults during ex.  Gradual loss of contractile strength due to  in Ca 2+ -myosin ATPase activity and possible myocardial ischemia.  The heart wall stiffens, which delays ventricular filling (  SV). Rely more on Frank-Starling mechanism.

13. 13 Stroke Volume and Cardiac Output  The elasticity of the major blood vessels and the heart  due to connective tissue changes.  Heart mass usually  and there are fibrotic changes in the heart valves with age.  Vascular stiffness  the peripheral resistance to blood flow, which  afterload of the heart.   peripheral resistance also raises SBP at rest and during exercise (no change in DBP).

14. 14 Arteriovenous Oxygen Difference  a-vO 2  with age, which  aerobic capacity.   from 16 vol%(20yrs) to 12 vol%(65yrs).  The  in a-vO 2 is due to:   fiber/capillary ratio   total hemoglobin   respiratory capacity of the muscle   in muscle mito mass   oxidative enzymes

15. 15 Circulatory Regulation  The capacity of the autonomic reflexes that control blood flow are diminished with age.   in circulation to the skin   in orthostatic tolerance in the elderly

16. 16 Endurance Training  Endurance training produces improvements in aerobic capacity in older individuals that are similar to those seen in younger individuals.  6 months of endurance training can improve VO 2 max by 20%.  Endurance training:   submaximal HR   resting and exercise SBP  faster recovery HR   SV,  CO

17. 17 Endurance Training  The rate and magnitude of CV adaptation to endurance exercise training depends on the type, intensity, frequency, and duration of exercise, as well as genetic factors.  Older women do not have the same  in SV as men with training. May be due to lack of estrogen in postmenopausal women.  They have similar improvements in VO 2 max as men, due to a larger a-vO 2 difference.

18. 18 Endurance Training  Assessing the effects of age on athletic performance is difficult.  As more masters athletes compete, the limitations produced by age will become more apparent.  Elderly individuals require a VO 2 max of 20 ml·kg -1 ·min -1 for an independent lifestyle.  A well structured endurance training program can  the fitness of an older person to this level.

19. 19 Pulmonary Function  The lung has a large reserve capacity to meet ventilation requirements during exercise.  This reserve capacity gradually  between 30 and 60 years (faster  in smokers).  Pulmonary function changes:   size of the alveoli (  vascularization)   elasticity of support structure   work of breathing  weakening of respiratory muscle

20. 20 Pulmonary Function  The deterioration in pulmonary function is similar in magnitude to that in the CV system.  Unless the  in pulmonary function is  by disease, ventilation remains adequate during exercise in older individuals.  Ventilation does not limit endurance performance.  Training  maximum ventilation.

21. 21 Skeletal System  Bone loss is a serious problem in older people, particularly women.  Women begin to lose bone mineral at 30 and men at 50 years of age.  Estrogen deficiency in postmenopausal women is though to accelerate bone loss in women over 45.  Although the exact mechanism of bone loss is not completely understood, the contributing factors are: inactivity, diet, skeletal blood flow and endocrine function.

22. 22 Skeletal System  Exercise is important in the prevention and treatment of osteoporosis.  Bones become stronger when stresses are placed on them.  Elderly male athletes have higher bone mineral content and density than non-athletes.  Excessive training (over training) can  bone mineral density.  Lifelong participation in physical activity may provide a buffer against bone loss.

23. 23 Joints  Joints become less stable and less mobile with age.  Aging is associated with: degradation of collagen fibers; cross-link formation; fibrous synovial membranes; joint surface deterioration;  viscosity of synovial fluid.  It is difficult to separate aging from accumulated wear and tear.  Trauma to the joint cartilage results in formation of scar tissue (impairs ROM).  ROM exercises can  flexibility.

24. 24 Skeletal Muscle  Loss of muscle mass and strength can have severe effects on the quality of life of the elderly.  Atrophied muscle contribute to obesity by  metabolic rate.  Poor muscular support  chance of falls.

25. 25 Strength  Muscle strength decreases appox 8% a decade after the age of 45.  Aging results in a  in isometric and dynamic strength and speed of movement.  Strength losses are due to:   size and # of muscle fibers  atrophy or loss of type II fibers   in the respiratory capacity of muscle   in connective tissue and fat

26. 26 Muscle Fiber Types  With age there is a selective loss of type II fibers, which  available strength and power.  Type II fibers  more rapidly in the lower than upper body.  The mechanisms involved in muscle contraction are also impaired:  less excitable, greater refractory period  conc of ATP and CP are   maximum contractile velocity 

27. 27 Muscle Biochemistry  There is loss of biochemical capacity with age.   in glycolytic enzymes (LDH).  There are no changes or slight  in oxidative enzymes.  Relative strength  with training are similar in young and old individuals.

28. 28 Exercise and Cardiovascular Disease Risk Factors  Exercise (even low intensity) has very significant health benefits in the elderly.  Exercise  blood insulin levels and improves glucose tolerance and insulin sensitivity.  Exercise  resting and exercise SBP.  Exercise improves plasma lipid profiles:  plasma triglyceride and cholesterol;  HDL.

29. 29 Body Composition and Stature  Body composition and stature change markedly with age.  Body weight  from age 20 to 60 and then .  Weight gain is due to an  in % body fat.  A greater proportion of body fat is stored internally rather than subcutaneously.  Stature  with age: rounding of the back; disc compression; vertebrae deterioration.  Exercise is very important in managing body composition in the elderly.

30. 30 Neural Function  Many neurophysiological changes occur with aging.  Age associated motor unit remodeling. Some denervated type II fibers become reinnervated by adjacent type I fibers.  Neural changes include:  visual acuity; hearing loss;  short-term memory; information processing;  reaction time.  Physical training has little effect on the deterioration of neural function.

31. 31 Exercise Prescription for the Elderly  The principles of exercise prescription are the same for everyone, however caution must be taken with the elderly to  the risk of injury.  Elderly individuals have more ECG abnormalities during exercise.  Care must be taken when determining the type and intensity of exercise.  Maximum heart rates vary considerably in the elderly (HR max : 105 - 200 for 60yr olds).

32. 32 Exercise Prescription for the Elderly Basic principles for exercise prescription with the elderly:  Careful progression in intensity and duration.  Warm up slowly and carefully.  Cool down slowly.  Static stretching after exercise.