The Elderly

Anthony DeLuca

Physical Activity and Life Cycle

Only 25% of elderly report being physically active 5 days/week for 30 mins/session.

How Aging Effects Nervous System

Skeletal Muscle- increased: risk of osteoporosis, arthritis. Decreased: mass, strength, speed, power, flexibility, type II fibers

Body Composition- increased: fat. Decreased: lean mass, bone mass.

Cardiovascular- increased: BP, risk for CVD. Decreased: cardiac output, VO2, dilatory capacity.

Metabolic- increased: glucose intolerance raising insulin levels leading to type 2 diabetes, risk of obesity.

Continued..

Respiratory- increased: chest wall/pulmonary artery stiffening, chest elastic recoil, lung pressure, dead space. Decreased: inspiratory/expiratory capacity, lung function, peak ventilation

Nervous- increased: risk of dementia, Alzheimer's. Decreased: blood distribution during exercise, cognition, memory, learning ability, reaction time, sleep, gait, balance, hearing, sight.

Energy Expenditure/Intake- increased: fat mass. Decreased: RMR, calorie expenditure, fat-free mass, calorie/protein intake.

Thermoregulation- decreased: ability to regulate body temp, amount of sweat per sweat gland, blood flow responses to exercise

Physiological Changes due to Aging

Cardiovascular- rest: increased BP, decreased HR. Max ex: decreased HR, cardiac output, O2 consumption, responses to stimulation, atrial-venous oxygen difference; no change in stroke volume

Respiratory- max ex: increased breathing frequency, residual volume; decreased max ventilation, tidal volume, vital capacity

Musculoskeletal- decreased muscle mass, strength, balance, coordination, bone density, elasticity in connective tissue

Metabolic- decreased glucose tolerance, insulin action, metabolic rate

Thermoregulation- decreased thirst, skin blood flow, sweat production

Chronic Medical Conditions in Elderly

Coronary Artery Disease- leading cause of death

Hypertension- most common Arthritis Diabetes Obesity

Pre-Exercise Training Evaluations

Chair Stand Step Ups Walking Speed Tandem Walk One-Leg Stand Functional Reach Timed Up and Go Range of Motion

Specific Exercise Testing

Cardiovascular- treadmill/ergometer, low intensity with small increases in work rate (peak VO2, HR, BP, ECG)

Strength- weight machines, modified 1RM focusing on muscles of ADL (load and reps)

ROM- gonimeter, measuring hip, ankle, knee, shoulder, low back, and hamstrings (degrees of motion)

Cardiovascular Exercise Prescription

Mode- walk, cycle, pool, aerobics, ADL’s Frequency- moderate 3x/week, vigorous 5x/week Intensity- low- 40% HRR or <5 on RPE scale to

10. moderate- 50-70% HRR or 5-6 RPE. vigorous- >70% HRR or 7-8 RPE.

Duration- low/moderate- 30 min continuous, 60 mins total. vigorous- 20 mins, can be in intervals

Considerations- start with short bouts at a low/moderate intensity building up to 30 continuous minutes. Make initial progress to increase compliance with program. Think about arthritis, osteoporosis, and heart disease

Strength Training Prescription

Mode- multistation machines, elastic bands, hand weights

Frequency- >2x/week Intensity- 5-6 RPE moderate, 7-8 RPE vigorous Duration- 10-15 reps for strength gains, up to 20

reps for endurance, 20-30 min/session Considerations- free weights may be difficult

so assistance/machines must be available. Focus mainly on large muscle groups used in ADL’s (legs, shoulders).

ROM Training Prescription Mode- static stretching and balance training Frequency- minimally 2x/week, maximally

everyday especially after an aerobic or resistance training

Intensity- mild stretch without pain, gradually increase range of stretch

Duration- 5-30 min total with two 30 sec bouts on each muscle group (all large muscle groups), yoga or tai chi for balance

Considerations- avoid ballistic stretching/ valsalva maneuver. Can be performed before and after exercise

Skeletal Muscle Power: A Critical Determinant of Physical

Functioning in Older Adults

What to Assess? Lower Extremity Muscle Power▪ Vertical jump on a platform force▪ Unloaded leg extensor power , isokinetic

dynamometry ▪ Pneumatic resistance training equipment

(provides high resistance without interia and dependency up gravity, no weight stack, just resistant force)

Short Physical Performance Battery Test

Characterizes lower extremity function using timed measures of standing balance, gait speed, and strength.

Studies show that the majority of elderly who take this test are classified as “mobility limited.”

The elderly with low muscular power were at greater risk of being “mobility limited” as compared to those with low muscular strength.

Muscle Contraction Velocity

Compared with muscle strength, contraction velocity of leg extensors has been shown to be a stronger predictor of lower intensity tasks such as habitual walking speed.

Higher leg press contraction velocity was associated with better performance on several measures of balance that are predictive of falling.

Physiological Determinants of Muscle Power and Mobility Limitations

With increasing age, there is a reduction in the number and size of type II muscle fibers (which can generate 4 times the power output of type I fibers)

Muscle Power loss also influenced by: Increases in muscle fat infiltration Changes in neuromuscular function Alterations in hormones

Changes in Muscle Mass and Quality

An experimental assessment was attempted to examine differences in muscle power generation within a specific age range in order to capture key factors that contribute to muscle power deficits and mobility limitations

Results Lower extremity muscle

Elders :- 95% reduction in muscle power and a 25% reduction

in muscle mass compared to healthy middle-aged participants.

- 65% reduction in muscular power and a 13% reduction in muscle mass compared to healthy older participants.

Healthy older subjects :- Estimated 2% muscle mass decline per year after age

65- Decline in muscle performance was 3 times higher

than the loss of muscle mass, suggesting a decline in muscle quality.

Restore Muscle Power

Resistance training that is designed to maximize muscle power output has shown that high velocity power training is: Realiable Well tolerated Effectively can improve lower extremity muscle

power in:1. Healthy men/women2. Older women with a self reported disability3. Older adults with mobility limitations 4. Women older than 80 years

High Velocity Resistance Program

After 12 weeks of high-velocity resistance training: increase in leg power in older men/women (50%-

141%) increase in lower extremity muscle power in older

adults with mobility limitations (25%) increase in specific leg extensor muscle power in

older adults with mobility limitations (46%) Peak power output improved equally (14-15%) in

all resistances of 20% 1RM, 50% 1RM and 80% 1RM in healthy older adults. - This suggests that power output can be increased with high velocity training at both low and high external resistances.

Continued…

Demonstrates relationship between the respective training intensities and improvements in muscle strength (20%) and muscle endurance (185%) when using the highest loading intensity of 80% 1RM.

12 weeks of explosive heavy resistance training with a loading intensity of 75%-80% 1-RM demonstrates: Substantial improvements in muscle power (28%). Gains in rapid muscle force-generating

characteristics in healthy older women between the ages of 80-89.

Power Training in Older Adults

Power training performed at a low intensity was associated with the greatest improvements in balance.

Exercises included weighted stair climbing. Increased leg power (17%) Increased stair climbing power (12%)

Conclusion

Trials have determined that: Muscle power > Muscle Strength – in

predicting functional performance in older adults High Contraction Velocity > Low Contraction

Velocity – in improving muscle power Exercise Programs targeted at improving leg

muscle power are:▪ Safe▪ Well tolerated▪ Effective, even among frail older adults

Sources

- Kieran F. Reid and Roger A. Fielding. “Skeletal Muscle Power: A critical determinant of Physical Functioning in Older Adults.” Nutrition, Exercise Physiology Laboratory, USDA Human Nutrition Research Center of Aging, Boston, MA. Sept 19, 2011.