Transcript Exercise and Aging

Physiological aging
process &role of exercise
Dr_R.heidari moghadam
(MD&PhD)
Exercise physiologist
DEFINITION OF AGING
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Old and aging depends on the age and
experience of the speaker.
Chronological age - number of years lived
Physiologic age - age by body function
Functional age - ability to contribute to
society
CHRONOLOGICAL
CATEGORIES
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Young-Old - (ages 65 - 74)
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Middle-Old - (ages 75 - 84)
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Old-Old - (age 85 and older)
PHYSIOLOGICAL
THEORIES OF
AGING
What causes the body to age?
PROGRAM THEORY
Cells replicate a specific number of
times and then die. Happens
again, and again in lab
experiments.
ERROR THEORY
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The structure of DNA
is altered as people age
Due to alterations,
DNA not read correctly
Results in transcription
and translation
malfunction
Results in
aging/illness/ cancer
directly, or indirectly
CELLULAR THEORY
Normal wear and tear causes cells
to function improperly
FREE RADICAL THEORY
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Lipids in cell
membranes are exposed
to radiation or free
radicals
Cell membrane ruptures
and cell dies
In test tubes this
actually occurs
NUTRITIONAL MODEL THEORY
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If animal fed 50-60%
less than it eats on its
own - lives longer
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Assumption: Lean
mass, as opposed to
adipose tissue results in
greater health
COLLAGEN THEORY OF AGING
As we age, collagen in body ages
also. Causes hypertension and
other organ malfunctions
MUTATING AUTO-IMMUNE
THEORY
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Cells have normal functions - secrete normal
proteins
As cells age - mutate and secretions viewed
as foreign by body
Solicits immune response
Shuts cell down
Cause biological errors and entire organ
malfunctions
NEURO-AGING THEORY
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All cells undergo
nervous system
degeneration
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Results in changes in
hormonal release
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Leads to decline in cell
function
NONE OF THESE
THEORIES
TOTALLY
ACCEPTED
Scientists hypothesize it might be
combination of several or all
PHYSIOLOGICAL AGING OF
THE HUMAN BODY BY
SYSTEMS
RESPIRATORY SYSTEM
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Lungs become more rigid
Pulmonary function
decreases
Number and size of
alveoli decreases
Vital capacity declines
Reduction in respiratory
fluid
Bony changes in chest
cavity
CARDIOVASCULAR SYSTEM
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Heart smaller and less elastic
with age
By age 70 cardiac output
reduced 70%
Heart valves become
sclerotic
Heart muscle more irritable
More arrhythmias
Arteries more rigid
Veins dilate
REPRODUCTIVE SYSTEM
Male:
 Reduced testosterone level
 Testes atrophy and soften
 Decrease in sperm production
 Seminal fluid decreases and
more viscous
 Erections take more time
 Refractory period after
ejaculation may lengthen to
days
REPRODUCTIVE SYSTEM
Female:
 Declining estrogen and
progesterone levels
 Ovulation ceases
 Introitus constricts and
loses elasticity
 Vagina atrophies - shorter
and drier
 Uterus shrinks
 Breasts pendulous and
lose elasticity
NEUROLOGICAL SYSTEM
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Neurons of central and peripheral
nervous system degenerate
Nerve transmission slows
Hypothalamus less effective in
regulating body temperature
Reduced REM sleep, decreased deep
sleep
After 50% lose 1% of neurons each
year
MUSCULOSCELETAL SYSTEM
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Adipose tissue increases with
age
Lean body mass decreases
Bone mineral content
diminished
Decrease in height from narrow
vertebral spaces
Less resilient connective tissue
Synovial fluid more viscous
May have exaggerated curvature
of spine
Exercise and Aging
Goals
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Develop an understanding of normal aging
physiology
Incorporate aerobic and resistance exercise into
treatment and prevention plans of the elderly
Appropriate pre-exercise assessment
Exercise and aging
physiology
Physiologic changes with aging
(Board Questions)
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Decreased
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Muscle mass
Muscle strength
Muscle power
Muscle endurance
Muscle contraction
velocity
Muscle mitochondrial
function
Muscle oxidative enzyme
capacity
Physiologic changes with aging
(Board Questions)
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Decreased
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Maximal and submaximal
aerobic capacity
Cardiac contractility
Maximal heart rate
Stroke volume and cardiac
output
Nerve conduction velocity
Balance
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Decreased
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Proprioception
Gait velocity
Gait stability
Insulin sensitivity
Glucose tolerance
Immune function
Bone mass/strength/density
Collagen cross-linkage,
thinning cartilage, tissue
elasticity
Physiologic Questions
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Increased
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Arterial stiffness
Myocardial stiffness
Systolic blood pressure
Diastolic blood pressure
Visceral fat mass
Total body fat
Intramuscular lipid
accumulation
Use It or Lose It
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Sedentary people lose large amounts of muscle
mass (20-40%)
6% per decade loss of Lean Body Mass (LBM)
Aerobic activity not sufficient to stop this loss
Only resistance training can overcome this loss
of mass and strength
Balance and flexibility training contributes to
exercise capacity
What is exercise?
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Lifestyle choices
Organized sports
Unstructured play
Household and
Occupational tasks
Increased Muscle Mass
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Endurance training
emphasis
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Walking isn’t enough
Progressive resistance
training
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DM prevention?
Dependency prevention?
Falls and fractures
Disuse
Sarcopenia
Frailty
Use It and Lose Less of It
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Resistance training improves strength by a range of
40-150%
Lean body mass increases 1-3 kg
Muscle fiber area 10-30%
Body composition
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Genetic, lifestyle and
disease factors
Metabolic, cardiovascular
and musculoskeletal
systems impacted
Lifestyle is under
patient’s control
Weight manangement
Burning Fat
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Decreases in total body adipose tissue
Aerobic and resistive training
 Energy restricted diets and/or high volume exercise
(5-7 hours/week)
 Visceral fat selectively mobilized
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What’s fat got to do with it?
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Metabolic syndrome
Vascular disease
Osteoarthritis
Gallbladder disease
Diabetes
Hypertension
Dyslipidemia
Sleep apnea
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Breast cancer
Colon cancer
Endometrial cancer
Impotence
Osteoarthritis
Depression
Disability
Exercise and prevention
Diabetes and Osteoporosis
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Insulin Resistance
Improves insulin sensitivity
 Detraining may reduce exercise effect
 Primary prevention demonstrated
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Osteoporosis prevention and treatment
Stabilization or increase in bone density in pre- and
postmenopausal women with resistive or weight
bearing exercise
 1-2% per year difference from controls
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Dyslipidemia
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Not a lot of data in elderly
No clear primary and secondary prevention data
Exercise associated with less atherogenic profiles
Duration and frequency factors
Weight loss (or fat loss) associated with
increased HDL
Gender differences with training
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Less training effect on HDL in women
Hypertension
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Most trials cross sectional and cohort
Lower pressures in active individuals
5-10 mmHg
 Type and intensity
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Greater training effect in those with mild to
moderate hypertension
6-7 mmHg drop in systolic and diastolic pressure
 Effect present in low-to-moderate exercise
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CVD
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Exercise training beneficial in CVD
Reduced claudication pain
 Greater walking distance
 Improved functional endpoints
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Benefit in selected patients with coronary artery
disease.
Arthritis
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Improved functional status
Faster gait
Lower depression
Less pain
Less medication use
Strength and endurance training benefit
Cancer
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Potential protective benefits with
Breast Cancer
 Colon Cancer
 Prostat
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Exercise treatment of chronic
disease
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May treat symptoms and disuse and not the
underlying disease
Parkinson’s
 COPD
 Claudication
 Chronic renal failure
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May reduce recurrence of disease
CVD
 Falls
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Exercise and emotional
health and well being
Emotional well being
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Genetic, social,
personality, and
psychological constructs
Leading cause of death
and disability in
developed countries
Exercise and Mental Health
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Positive psychologic attributes
Lower prevalence and incidence of depressive
symptoms
Reversal of hippocampal volume loss?
Reversal of cognitive loss?
14 randomized, controlled trials:
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Aerobic and resistance training
Higher intensities
Meaningful improvements in depression
Response rates of 31-88%
Equipotent to standard treatment
Exercise and disability
Function relates to strength
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Non-linear relationship between strength and function
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EPESE Study:
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Concept of Threshold
Physically active patients at baseline less likely to develop
disability
Exercise improves functional limitations
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Functional balance tasks
Gait speed
Arthritis
Exercise and longevity
Exercise Evaluation
Contraindications
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Relative
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Acute illness
Undiagnosed chest pain
Uncontrolled diabetes
Uncontrolled
hypertension
Uncontrolled asthma
Uncontrolled CHF
Musculoskeletal problems
Weight loss and falls
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Absolute
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Inoperable Aortic
Aneurysm
Cerebral aneurysm
Malignant ventricular
arrhythmia
Critical aortic stenosis
End-stage CHF
Terminal illness
Behavioral problems
Exercise Prescription
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Modes
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General activities
Aerobic
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Static stretch
Balance
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Risk assessment
Dynamic and static balance
Most days
Intensity
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30 minutes
Frequency
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Supervision/technique
Benefit with one set
Flexibility
Duration
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Resistance
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Mode governed by:
Walking
Sports
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Borg Scale 12-14
55-75% of MHR
MHR
ACSM guidelines for healthy aerobic
activity
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Exercise 3-5 days each week
Warm up 5-10 minutes before aerobic activity
Maintain intensity for 30-45 minutes
Gradually decrease intensity of workout, then
stretch to cool down during last 5-10 minutes
If weight loss is goal, 30 minutes five days a
week
Aging and Aerobic Capacity
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Peak between 15-30
Declines with age
Approximately 10% per decade after age 25-30
Masters Athletes: 5% per decade
 Overall: 0.55 decline per year in VO2 max
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Anaerobic threshold: occurs at lower work rates
Benefits of Regular Physical Activity
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Cardiovascular health
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Cholesterol, HDL, LDL, VO2,RHR
Muscular health
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Strengthens bone
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LBM enhanced/preserved
 BMR
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improved/maintained
Endurance/strength improves
More Benefits of Regular Physical Activity
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Reduces health risks associated with obesity
Enhances insulin action
 Reduces body fat
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Reduces cancers risk
Reduces susceptibility to infections
Improves peristaltic functions
Fewer injuries
Reduced health care costs
Psychological health
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Stress and depression
Improved QOL
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