Lecture 3 Flashcards
risk factors for chronic disease modifiable
Unhealthy diet
Physical inactivity
Tobacco use/alcohol
Overweight
risk factors for chronic disease non modifiable
Age
Gender
Family history
Ethnicity
cardiovascular changes with age
- vessel changes
- heart changes
- blood pressure
- cardiac output
- stroke volume
- Vo2 max
vessel changes
-Arteriosclerosis
-Atherosclerosis
Vein valves deteriorate = varicose veins and blood pooling, fibrosis
-Capillary walls thicken reducing gas exchange
-decreased responsiveness to beta adrenergic receptor stimulation,
a decreased reactivity to baroreceptors and chemoreceptors, and
an increase in circulating catecholamines
Arteriosclerosis
reduced elasticity of aorta
and great arteries = increased resistance (BP),
larger left ventricle
Atherosclerosis
build up of fatty plaques
(lifestyle related) DVT, PVD
heart changes with age
-Lengthened contraction period
-Ischemic myocardium, cardiac cells hypertrophy
-Heart valves become thicker and become stiff
-Loss of atrial pacemaker cells in SA node = decreased intrinsic heart
rate = more likely to have arrhythmias
-Incomplete relaxation during filling (approx 50% between ages 20 and
70)
-Left ventricle hypertrophy
heart rate changes
-Resting HR decreases with age
-Max heart rate decreases 5-10 bpm/decade
(major contributor to decline in oxygen use)
-Slower heart rate recovery after exercise
blood pressure changes
-Patient can be diagnosed as hypertensive if mean
systolic measure is > 135 mmHg and mean diastolic
measure is >85mmHg
-BP increases with age because of increased rigidity
of vessels (10-40 mmHg elevation in both systolic
and diastolic) (CSEP)
-Baroreceptors (carotid and aortic) less sensitive to
BP changes – can cause orthostatic hypotension
cardiac output changes
total amt of blood ejected from each ventricle/minute -Small change with age -Represents ability of the CV system to deliver O2 to working muscles CO = SV X HR
stroke volume changes
-amount of blood pumped out of
each ventricle with each beat
-Moderate decline with age
Vo2 max changes
-Max. capacity to transport O2 during exercise
-Max. oxygen consumption decreases 5-15% per decade after age
30 (Elia, 1991)
-Depends on CO, lung capacity, amt of 02 muscles can use (fibers,
capilarization)
-Highly trained individuals may show little or no decline with age
-Can be increased with moderate to vigorous exercise
respiratory changes with age
-Loss of elastic recoil in lung tissue
-Muscles of chest wall become more stiff, less
pliable, atrophied
• Kyphosis reduces lung capacity
• Ossification of costochondral
cartilage
-Small change in alveoli surface
area (for gas exchange)
-Diminished ability to breathe
deeply, cough and exhale
-Increased size and number of mucous glands in
bronchial tree – narrow airways
-Decrease in ciliary function (decreased immune
response = increase chance of infection)
lung volume changes
Increased residual volume (amt of air left in -lungs after
complete expiration) esp. with lower chest wall
compliance
-Decreased expiratory reserve volume (amt of air exhaled
with normal expiration)
-Decreased vital capacity (volume of air that can be
expelled after full inspiration)
-4-5% per decade decrease after age 25
general physical changes
-Height loss: related to aging changes in the bones, muscles, and
joints. Typical loss: about 1 cm every 10 years after age 40. More quickly after age 70. You may lose a total of 1 to 3 inches as you age
-Body composition: % body fat increases while lean mass and
bone density decrease. Body weight may not change
fat men and women
- Fat internalized in trunk (esp. men)
- Women increase fat in lower body
uses for fat
- Source of energy
- Storage for some vitamins (storage fat)
- Cell membrane integrity
- Protection of internal organs
- Brain and nervous system component (essential fat)
- Insulation
obesity is associated with higher levels of
- Some cancers (breast, ovarian, colon)
- Hypertension
- Osteoarthritis
- Cardiovascular disease and stroke
- T2 Diabetes
- Fatty liver disease
BMI for seniors
BMI healthiest between 27 – 30 kg/m2
overweight category
how much weight do you have to lose to improve health
Some studies say as little as 2-5% of current
weight - better outcomes with 10%
what are bones good for
- Structure
- Protection
- Mobility
- Calcium storage
with age comes height loss
Height loss:
- Disc compression
- Increased kyphosis
- Muscular weakness
- Bone mass loss 1-3% per year after menopause
muscle fiber
- single muscle cell
- collection of myofibrils
myofibrils
collection of myofilaments
myofilaments
actin (thin) filament
myosin (thick) filament
changes in muscle
-sarcopenia
-Total muscle mass decreases with age (40% loss of
muscle mass, 30% decrease in strength- 1-2% per year after age 50
-More pronounced decline in men than women
-Decrease in number of muscle fibres
-Muscle fibre size decreases slightly (atrophy)
-Type II (fast twitch) fibres lost, but may be re-innervated
by slow twitch motor unit nerve endings
-Reduced number of motor
units (motor neuron death in
spinal cord)
-Capillarization remains
unchanged if active
-Number of muscle fibres per
motor neuron increases with
age
-Mitochondrial function
decreases
sarcopenia
age-related loss of skeletal mass and function D
strength
-Peak strength at around age 25
-Plateaus 30-40
-30% loss of strength by age 70
-Contraction and relaxation of muscle takes longer
-Max contraction velocity reduced
-Loss of isometric and dynamic muscle strength (40%
in leg and 30% in arm between ages 30 and 80)
maintained
-Muscles used daily
-Isometric strength
-Eccentric contraction
-Slow velocity contractions
-Repeated low level
contractions
-Strength using small joint
angles
greater decline
-Muscles used less
-Dynamic strength
-Concentric contraction
-Rapid velocity contraction
-Power production
-Strength using large joint
angles
joints
-degradation of the articular cartilage
-thickening of the subchondral bone with accumulation
of poorly mineralized matrix,
-osteophyte formation at the margins of joint surfaces,
-variable degrees of synovial inflammation, reduced
vascularity
-degeneration of ligaments and, in the knee the menisci,
with eventual ligamentous rupture and meniscal
extrusion
-hypertrophy of the joint capsule contributing to joint
enlargement
-Synovial fluid less viscous
what does the nervous system do
Receives (through 5 senses), processes and stores
sensory information from inside and outside the body,
and decides what to do with that information
-Along with endocrine system, provides communication
between cells of the body
central nervous system changes
-Reduction in cerebral blood flow (decreases about 10-20%, in
proportion to neuronal loss)
-Decline in memory, reasoning, perception
-Disturbed sleep/wake cycle
-Increased threshold for many sensory modalities including
touch, temperature, sensation, proprioception, hearing, and
vision
-Overall reduction in brain tissue volume due to decreased neuronal
size
-Number of neurotransmitters and neuroreceptors diminished even
in absence of dementia or other neurological diseases
-acetylcholine and serotonin in the cortex, dopamine receptors in
the neostriata, and dopamine levels in the substantia nigra and
neostriata.
other age related changes
-General reduction in hormone production affects use of
carbohydrate and proteins for fuel
-Decreased ability to gain muscle
-Metabolism decreases – more difficult to manage weight
-Altered glucose tolerance
-Impaired thermoregulation
-Hyperlipidemia common
progressive RT study
- Older people who exercise against a force (machines, free weights,
bands) become stronger - Improve walking, stair climbing and standing up from a chair performance
- Also improved complex daily activities such as bathing
- Reduced pain in those with osteoarthritis
- Insufficient evidence to comment on long term risks or effects of PRT
HITT study
-Same benefits as traditional endurance training for seniors (found
in some studies):
• Increased lipolysis and enhanced insulin sensitivity, improved VO2
peak and stroke volume
• Because of short bouts, less time for hemodynamic response (BP)
• Big benefit – less time to workout
