Aging and Exercise Flashcards
1
Q
age of highest strength levels
A
20-40 (women and men)
- muscle cross sectional area is largest
- concentric strength of most muscle groups declines, slowly at first, then more rapidly after middle age
- capacity for power generation declines faster than that for maximal strength
2
Q
declines in strength
A
- eccentric strength decline begins at a later age and progresses more slowly than concentric strength
- arm strength deteriorates more slowly than leg strength (less walking around/movement lower extremity)
- strength loss relates to limited mobility and fitness status, potential for increased incidence of accidents
3
Q
muscle mass decrease
A
- begins to decrease at approximately age 30, decreasing by 10% by age 50
- muscle area usually parallels reduced fiber size, particularly reduced size and number of fast twitch fibers
4
Q
motor unit remodeling and muscle mass decrease
A
motor unit remodeling involves motor endplate repair and reconstruction gradually deteriorates in old age
- leads to denervation muscle atrophy which, magnified by reduced physical activity, progressively reduces muscle cross section(strength), mass, and function
- affects type II muscle fibers the most
- leads to an increase in number of type 1 muscle fibers
5
Q
sarcoponeia
A
losing muscle fibers
6
Q
loss muscle fiber type
A
-lose fastest twitch (type IIB) the fastest, slow twitch maintained with old age
7
Q
protein synthesis during aging
A
-slowed during aging
8
Q
neural function
A
- aging leads to a 40% decline in spinal cord axons number and a 10% decline in nerve conduction velocity
- these changes likely contribute to the age-related decrement in neuromuscular performance assessed by simple and complex reaction and movement times
- a physically active lifestyle and specific exercise training affects neuromuscular functions positively at any age to slow the age-related decline in cognitive performance associated with speed of information processing
- overall reduction of nervous system ability to conduct impulses
9
Q
endocrine function
A
- 40% of those ages 65-75 and 50% of >80 have impaired glucose tolerance that leads to type II diabetes
- pituitary gland decreases release of thyroid stimulating hormone thyrotropin, which affects metabolic function
- hormonal systems changed due to aging
- -hypothalamic-pituitary-gonadal axis, leading to menopause and andropause
- -adrenal cortex leading to a reduced output of DHEA
- -growth hormone/insulin-like growth factor axis leading to somatopause
10
Q
age dependent changes in pulmonary function
A
major age related changes in pulmonary function -decrease elastic recoil of lung tissue --changes lung volumes --less surface area for gas exchange -stiffening of chest wall -decrease intervertebral space -weakening of respiratory muscle TV DOES NOT CHANGE WITH AGE -ability to take in as much air decreases, reserves impacted
11
Q
pulmonary response to exercise
A
older adults display an attenuated response to exercise
- more flow limitation
- higher ventilatory rates
- approach maximal inspiratory pressure
- increased expiratory resistance
- approach TLC
- response remains the same, just not to the same extent
12
Q
pulmonary function summary
A
- mechanical constraints cause deterioration in static and dynamic lung function
- pulmonary ventilation and gas exchange kinetics during the transition from rest to submaximal exercise slow substantially
- in elderly men, aerobic training increases gas exchange kinetics to levels that approach values for fit young adults and older endurance-trained athletes demonstrate greater pulmonary functional capacity than sedentary peers
- -basically still have improvements with old age
13
Q
cardiovascular function
A
- VO2 max declines 1% per year and occurs twice as fast in sedentary compared to physically active
- decline in aerobic power with aging
- maximum exercise heart rate declines with age
- maximum cardiac output decreases in the trained and untrained due to lower max heart rate and stroke volume
- compliance of large arteries declines from changes in the arterial wall’s structural and nonstructural properties
- decreased capillary:muscle fiber ratio and arterial cross-sectional area causes lower blood flow to active muscle
14
Q
cardiac output during exercise
A
EDV-slight increase
ESV-still increases, just not as much
-contractility decreases, dont eject as much blood, CO decreases, HR does not reach same values as YA
15
Q
cardiovascular function summary
A
- attenuated response to exercise largely due to changes in cardiac output
- with aerobic exercise training many of those physiologic changes can be partially reversed
- -parallels improvements in YA
