Transcript Vibration
Aging and Exercise
Brooks Chpt 32
Brooks Chpt 19
Rogers and Evans
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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.
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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.
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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.
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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.
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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.
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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.
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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)
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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.
VO2max, 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.
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Maximal Oxygen Consumption
VO2max approx 30% between 20 and 65
rate of decline is greatest after age 40
decreases in VO2max is quite variable
VO2max due to ’s in HRmax, SV, power
output, fat-free mass, a-vO2 difference.
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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.
b-adrenergic responsiveness with age, this
will HRmax.
Age related in HRmax is partially due to
deconditioning and loss of muscle mass.
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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 Ca2+-myosin ATPase activity and
possible myocardial ischemia.
The heart wall stiffens, which delays
ventricular filling ( SV). Rely more on
Frank-Starling mechanism.
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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).
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Arteriovenous Oxygen Difference
a-vO2 with age, which aerobic capacity.
from 16 vol%(20yrs) to 12 vol%(65yrs).
The in a-vO2 is due to:
fiber/capillary ratio
total hemoglobin
respiratory capacity of the muscle
in muscle mito mass
oxidative enzymes
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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
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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
VO2max by 20%.
Endurance training:
submaximal HR
resting and exercise SBP
faster recovery HR
SV, CO
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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 VO2max as
men, due to a larger a-vO2 difference.
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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 VO2max 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.
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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
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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.
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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. 21
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.
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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.
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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.
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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
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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
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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.
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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.
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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.
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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.
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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 (HRmax : 105 - 200 for 60yr olds).
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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.
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