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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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