week 6

Question 1

by 2030, [ ]% of population will be over the age of 65

Answer 1

20%

Question 2

nearly [ ]% of adults have reported little or no leisure-time activity

Answer 2

• 60%
• sedentary life may be to blame for as many as 200,000 death in US per year
• yet older adults are the most likely to benefit from regular exercise

Question 3

changes in peripheral nervous system with age

Answer 3

• with aging, nerves undergo structural, functional, and biochemical changes
• loss of myelinated nerve fibers
• decreased ability of nerve to regenerate and reinnervate muscle

Question 4

changes in central nervous system with aging

Answer 4

• deficits in muscle activation

Question 5

changes in MSK system - soft tissue with age

Answer 5

• changes in ST flexibility/compliance
• ligaments and tendons:
• collagen becomes more cross-linked (more stiffness)
• elastin udnergoes structural changes
• decreased water content of connective tissue (less flexibility)

Question 6

changes in MSK system - changes in bone density with age

Answer 6

• osteopenia: between 1 and 2.5 SD below average bone density
• osteoporosis: less than 2.5 SD below average
• progressive loss of bone mineral density leads to a disruption in microarchitecture, more susceptible to fracture (women > men)

Question 7

MSK changes - muscle with age

Answer 7

• changse in muscle strength
• largely drive by sarcopenia: age-related loss of muscle mass
• morphological, physiological, central activation
• greater change in LE than UE
• proximal before distal muscles affected

Question 8

morphological changes to muscle with age

Answer 8

• decreased total number of fibers (type I and II)
• preferential atrophy of type II fibers
• loss of motor units with increase in size of remaining motor units - lose sensitivity to grade finer motor units
• increase in intramuscular fat
• size of vastus lateralis of older individuals was 18% smaller and total number of fibers was 25% lower

Question 9

physiological changes to muscle with age

Answer 9

• slower contractile properties: slower time to peak tension, slower rate of relaxation
• decreased maximum shortening velocity
• minimal changes in metabolism with active lifestyle if muscle mass is fully maintained

Question 10

central activation deficits in muscle with age

Answer 10

• muscle activation deficits may magnify weakness from morphological and physiological causes - ability to activate decreases
• age-related central activation deficits vary from muscle to muscle: bicep and quadricep 5-6% deficits in healthy older adults

Question 11

protein needs with age

Answer 11

• evidence for greater protein turnover with increasing age
• inadequate dietary protein intake may be an important cause of sarcopenia
• need 0.5g of protein/pound of body weight

Question 12

changes in mobility and balance with age

Answer 12

• changes in joint stiffness
• increase co-contraction of antagonist muscles
• changes in vestibular ocular reflex
• slower postural responses - 20-30 ms delay

Question 13

strength training for oldies can

Answer 13

• offset age-related loss of muscle mass and strength
• decrease risk for osteoporosis
• increase basal metabolic rate

Question 14

endurance training for oldies

Answer 14

• purpose is to improve CV health
• older adults do not need endurance training to increase endurance of muscle but rather to improve CV response to aerobic exercise
• (older muscle doesn’t fatigue as fast and is more endurant, so target of endurance training is truly CV)

Question 15

age-related cardiac structural changes

Answer 15

• progressive degeneration of cardiac structures:
• loss of elasticity
• fibrotic changes in vales of heart
• infiltration with amyloid
• decreased contractility of the heart’s left ventricular wall

so pumping capacity decreases with age

Question 16

age-related changes in blood vessels

Answer 16

• decrease elasticity of arteries
• decreased elasticity of veins
• decreased elasticity of aorta

Question 17

age related changes in electrical conduction system of the heart

Answer 17

• decrease number of pacemaker cells in SA node
• increase in elastic and collagenous tissue in all parts of conduction system
• fat infiltration

Question 18

VO2 max with age

Answer 18

• for an 85 YO to live independently, need a minimum aerobic capcity of:
• 18 ml/O2/kg/min for men
• 15 ml/O2/kg/min for women

Question 19

VO2 max change with age

Answer 19

• 4-5.5 decrease each decade for men
• 2-3.5 decrease each decade for women
• older adults still have capacity to increase VO2 max considerabily with proper training intensity
• 10-15% gains when training mode matches testing mode