Final - Exercise and Aging Flashcards
What is aging?
- a process or group of processes occurring in living organisms that with the passage of time, lead to a loss of adaptability, functional impairment, and eventually, death
- difficulty is teasing out the effect of primary aging from concurrent disease, physical inactivity and other environmental factors
who is an “older” adult?
someone >65 years old or someone 50-64 with clinically significant conditions or physical limitations that affect movement, physical fitness or physical activity
physically elite older adults
- sports competition
- senior olympics
- high risk and power sports
physically fit older adults
- moderate physical work
- all endurance sports and games
- most hobbies
physically independent older adults
- very light physical work
- hobbies
- low physical demand activities
- can pass all IADL
Physically frail
- light housekeeping
- food preparation
- grocery shopping
- can pass some IADLs and all basic ADLs
physically dependent older adults
- cannot pass some or all basic ADLs
- needs home or institutional care
definition of physically frail
severe impairments in strength, mobility, balance and endurance due to muscles that are weka and highly fatiguable
neuromuscular variables associated with aging:
- decrease in number and size of motor neurons
- decrease in conduction velocity and maximum frequency
- increase in the excitability threshold of muscle
- decreased proprioception and vestibular functions
result of aging changes:
- slower reaction times
- control of movement is less precise
- balance abnormalities
- increased risk of falling
sarcopenia
loss of muscle mass with aging
contributes important to decreases in muscular strength with aging
strength loss can lead to ….
limited mobility and increased risk of falling
Muscle mass decreases with aging
- decrease in total number of muscle fibers –> denervation leads to degeneration of muscle fibers
- contractile protein content dependent on activity status
When does number of muscle fibers begin to change?
age 50
Does strength or muscle mass decrease at a faster rate?
strength
what does the decreased cross bridge kinetics cause?
Slowed contractile velocity and thus isokinetic force (dynamic strength)
What occurs to muscle mass and strength if activity is low?
reduction in muscle contractile protein (atrophy) may also contribute to decreased muscle mass strength
What can blunt “normal” loss of muscle mass and strength with aging?
- resistance training
- cannot completely prevent it but increases strength due to neural adaptation and increases in muscle mass
Can training effect be seen in the elderly (>75)?
Yes
Substantial gains can be seen with frail elderly
Positive Effects of Resistance Training in Older Adults
- Maintenance or increase in muscular strength, endurance, flexibility
- Maintain or regain mobility (strength for ADLs)
- Decrease falling risk
General Resistance Training Recommendations for Healthy Older Adults
- 2-3 sessions/week (48hr rest between)
- between moderate and vigorous intensity (5-8 RPE, 40-50% 1RM then progress to 60-80%)
- 8-10 exercises, 1 or more sets or 10-15 reps
Recommendations for Older, Frail Population
- Train major muscle groups of upper and lower extremities in trunk
- Initial intensity light (30-40% 1RM for 10-20 reps, or as tolerated)
- 2-3 days/week with 2-3 sets
- incorporate balance training
- high degree of supervision and training
What happens to VO2 max with age?
Declines
- move it or lose it
- rate of decline in VO2max in endurance trained individuals is determined largely by the corresponding reduction in overall habitual activity
Summary of Functional Capacity and Aging
- Reductions in physical function after 60 in part due to declining intrinsic physiologic task capacity
- Large muscle performance relatively well-maintained until 60-70 on average (co-morbidities accelerate functional capacity loss)
What causes much of the age-related reductions in large-muscle endurance performance?
reductions in VO2max
What is an important factor in maintaining general health and QOL as we age?
exercise
CV and respiratory alterations with aging
- increased resting and exercise BP
- lower maximal CO, HR, and VO2max
- higher residual capacity, lower vital capacity, and lower max Ve response
At a submax ABSOLUTE exercise intensity, older adults have:
- somewhat lower CO, due to SV
- Same VO2 (assuming same economy) and HR
- a widening of a-v O2 difference
- higher BP
- higher TPR
CV adaptations to training with aging
- increase in max SV (ONLY IN MEN)
- Adaptations at the muscle include increased oxygen extraction (explains increase in VO2max in women) and increased capillary density and oxidative capacity
- reduction in rest HR and BP
Why does aging increase the work of breathing?
- Due to increased airflow resistance and chest wall stiffness
- Work of breathing ma increase to 15% of VO2max
What occurs to alveoli with aging?
- loss of alveoli and increased size of alveoli
- promotes decrease in forced vital capacity with increased residual volume
- Air trapping
- Emphysemic change
What occurs to maximal ventilatory capacity with aging?
decreases
What occurs to Ve/VO2 ratio in older persons
- increases
- older adults rely more on increasing breathing frequency during exercise, as tidal volume is reduced
Relative intensity for aerobic exercise for older adults
Moderate 5-6
Vigorous 7-8
Prescribing Exercise for Healthy Older Adults
Intensity: 5-6 (40-60%) for mod, 7-8 (60-89%) vigorous
Frequency: min 5 d/week moderate, 3 d/week vigorous
Time: mod 150-300 min, vig 75-100 min
Type: may need to substitute non WB’ing exercise
Progression: relatively slowly; emphasizing increased duration rather than intensity
Why does the ability to maintain high levels of training decrease with aging?
decreases in motivation, time, injury, “intrinsic” drive to exercise
Submaximal Response to dynamic exercise in aging
aging individuals respond similarly to submax exercise when matched for relative exercise intensity (% of VO2max)
