Exercise for the Special Population

1. Exercise for the Special Population

2. We will consider: • Global Aging • Physiological Changes associated with aging • Benefits of exercises in older adults • Contraindications to exercise training • Principles of training • Evaluation tools • Osteoporosis

3. Useful Resource Link • World Health Organization http://www.who.int/hpr/ageing/index.htm • ACSM Exercise and Physical Activity for Older Adults – Position Stand http://www.msse.org/ • Elderly Health Service (Hong Kong) http://www.info.gov.hk/elderly/english/index.htm

4. Life Expectancy at Birth (male & female), 1978-1998 (HK)

5. Population Ageing - facts By 2020, • the number of elderly people worldwide will reach more than 1000 million • elderly people will represent around 25% of the total population (currently 20%)

6. Regional Ageing – facts By 2020, • projected proportion of population aged 60 and over is 17% in East Asia and 10% in South Asia • China is one of the largest elderly population in the world (230 million)

7. Ageing, morbidity & mortality By 2020, • 3/4 of all deaths ageing-related • Most caused by non-communicable diseases, such as diseases of the circulatory system, cancers and diabetes

8. What happens when one gets older…

9. Effect of Aging –Physiological Considerations • Cardiovascular system • Pulmonary system • Musculoskeletal system • Nervous system • Body composition • Renal function, thermoregulation • Immune function • Psychological function

10. Cardiovascular Function • VO2 max  by 5-15% per decade after age 25 • Resting stroke volume  • Maximal HR  6-10 beats/min/decade • Resting cardiac output  1% per year • Myofilament disorganization, changes in mitochondrial structure   oxidative capacity   a-vO2 difference • Anaerobic capacity 

11. Pulmonary Function • Lung compliance  • Residual volume  30-50% • Vital capacity  40-50% by age of 70

12. Musculoskeletal Function Muscle • Sarcopenia (loss of muscle mass) reduction in muscle strength  functional capacity • Gradual and selective loss of muscle fibers (more marked in Type II muscle fiber) • Muscle strength and walking speed correlation strong

13. Musculoskeletal Function Bone • Slow but continuous loss of trabecular BMD beginning ~ 3rd decade •  in cortical BMD ~ menopausal years • Note: • Peripheral or cortical skeleton constitutes 80% of skeletal mass (shafts of long bone) • Trabecular or cancellous bone constitutes 70% by volume of the central skeleton

14. Osteoporosis • Low bone mass and mircoarchitectural deterioration of bone tissue  bone fragility  bone fracture • Expressed as BMC or BMD • Common measurement techniques – • Dual energy x-ray absroptiometry (DEXA) • Computed tomography • Site measured: Lx vertebrae, proximal femur, forearm

15. Changes in bone mass • Bone is gained during adolescence • Peak bone density at late adolescence • Reaches plateau sometime during 3rd decade • Stable till ~ age 50 • Then progressive, gradual loss

16. Regulation of BMD • Physical activity • Reproductive endorcine status • Calcium nutriture

17. Musculoskeletal Function Soft tissue & Joints • Flexibility  - changes in collagen, decrease in extensibility • Range of motion at joints 

18. Nervous System • Vestibular, visual and somatosensory changes, inappropriate feedback to postural control centers • Nerve conduction velocities and reaction times  15% by 70 years • Muscle effectors lack the capacity to respond • Postural stability affected

19. Other functions •  basal metabolic rate  relative  body fat •  renal function 30-50% between 30-70 years (affect acid-base control, glucose tolerance, drug clearance) • Reduced sweating capacity •  in immune system function   resistance to pathogens • Vision

20. Psychological Function •  cognitive function (decline in CNS) •  perception of control or self-efficacy • Depression

21. Benefits of Physical Activity in Older Adults

22. Endurance training • Can achieve same 10-30%  VO2 max as young adults (result of improvement of CO and a-vO2 difference) • Lower BP •  body fat • Improve glucose tolerance • Improve submaximal performance • Reduction in risk factors associated with diseases

23. Strength training • Offset loss of muscle mass and strength • Positive effect on bone density • Reduction in risk of osteoporosis • Improve postural stability • Decrease risk of falling • Improve flexibility and ROM

24. Relationship • Muscle strength, muscle mass and BMD – STRENGTH is the key factor • Age, activity and BMD – WEIGHT-BEARING is the key factor • Positiveassociation between BMDand MUSCLE STRENGTH

25. Physical Activity & Bone Mass • Positive correlation between activity level & BMD • Loads other than generated by gravity (e.g. muscular pull) actively stimulate bone deposition •  activity associated with lower rate of age-related bone loss

26. Muscle Mass, Strength & BMD • Positive correlation (e.g. BMD lumbar spine with back extensor strength) • Site-specific

27. Benefits • Preserve cognitive function (e.g. memory, attention, reaction time) • Alleviate depression symptoms and behaviour • Improve concept of personal control and self-efficacy

28. Think about… • Health vs. Illness • Functional capacity • Quality of life • Social contacts • Cerebral function

29. Contraindications to exercise testing and training • Absolute contraindications – myocardial infarction, unstable angina, uncontrolled arrhythmias, third degree heart block, acute congestive heart failure • Relative contraindications -  BP, valvular heart disease, ventricular ectopy, uncontrolled metabolic disease • Precautions – diabetes, hypertension, obesity, left ventricular dysfunction

30. Principles of training • Specificity – response to loading but does not impose orthopedic stress • Overload – training stimulus exceed normal loading without overtaxing • Reversibility – positive effect lost if program discontinued • Ceiling effect and diminishing returns

31. Principles of training Great variability depending on pathology. • F – Emphasize increase frequency (5-7 days/week) • I– < 75 years: > 7 METS > 75 years: < 4 METS RPE useful indication • T– 20-40 min/session (up to 60 min, if possible) • T– whole body activities, multi-joint activities, (enjoyable, company)

32. Aerobic Conditioning • Light intensity : 35-54% HRmax • Moderate intensity: 55-69 % HRmax • Hard intensity: 70-89% % HRmax • Very hard intensity:  90% HRmax • Duration: 30 min • Activities: walking, cycling, dancing, swimming

33. Resistance training • Directed at large muscle groups important for ADL • About 8-10 exercises • Each set 8-12 repetitions • 8-12RM for strength training and 20RM for endurance • RPE rating 12-13 (somewhat hard) • Frequency: at least 2x per week (48 hours rest in between sessions) • Duration of 20-30 minutes • Progress every 2-3 weeks

34. Exercise to improve bone health • Wolff’s law - Bone will accommodate the habitual stress that are imposed on it • WB exercise – mechanical stimuli to maintain or improve bone health • Progressive resistance training >> effective than aerobic training

35. Flexibility • Perform on major joints of the body • Slow movement, followed by static stretch 10-30 seconds • 3-5 repetitions • Frequency: 3-5 times per week (preferably daily) • As warm-up and cool-down before exercises • Duration: 15-30 minutes

36. Progression Think about the following parameters: • Duration • Frequency • Resistance • Number of repetitions, time • Complexity • Static/dynamic balance, base of support, line of support, centre of gravity

37. Think about… • Physical; • Psychological / behavioral; • Environmental ; • Social and cultural determinants Adherence to Exercise

38. Other practical issues • Pre-existing medical conditions • Maintain normal breathing patterns • No ballistic movements • Equipment (hand-grip, well-cushioned mats etc.), base of support, lighting, ventilation • Gradual progression, increase duration rather than intensity (older adults) • Accessible, convenient, SAFE

39. Evaluation Tools

40. Simple Fitness Tests • Lower body strength – 30 second chair stand • Endurance – 2 minute step-in-place • Flexibility – sit and reach Norm Scores provided http://www.acsm.org/activeaging.htm

41. Common functional tests • Timed up and go test • 6-minute walk • Berg balance • Handgrip strength