week 6 Flashcards
1
Q
by 2030, [ ]% of population will be over the age of 65
A
20%
2
Q
nearly [ ]% of adults have reported little or no leisure-time activity
A
- 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
3
Q
changes in peripheral nervous system with age
A
- with aging, nerves undergo structural, functional, and biochemical changes
- loss of myelinated nerve fibers
- decreased ability of nerve to regenerate and reinnervate muscle
4
Q
changes in central nervous system with aging
A
- deficits in muscle activation
5
Q
changes in MSK system - soft tissue with age
A
- 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)
6
Q
changes in MSK system - changes in bone density with age
A
- 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)
7
Q
MSK changes - muscle with age
A
- 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
8
Q
morphological changes to muscle with age
A
- 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
9
Q
physiological changes to muscle with age
A
- 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
10
Q
central activation deficits in muscle with age
A
- 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
11
Q
protein needs with age
A
- 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
12
Q
changes in mobility and balance with age
A
- changes in joint stiffness
- increase co-contraction of antagonist muscles
- changes in vestibular ocular reflex
- slower postural responses - 20-30 ms delay
13
Q
strength training for oldies can
A
- offset age-related loss of muscle mass and strength
- decrease risk for osteoporosis
- increase basal metabolic rate
14
Q
endurance training for oldies
A
- 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)
15
Q
age-related cardiac structural changes
A
- 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
