Aging & Effects on CV system, muscles & Exercising

Question 1

Heart Rate & aging

Answer 1

• Resting HR: little or no change
• Lower maximal HR
• Decreased pacemaker cells in SA node (not as efficient)
• Decreased end diastolic volume

Question 2

VO2 max

Answer 2

decreased due to decreased SV & HR

- decreases blood flow to muscles, capillary density & arterial distensibility (high BP)

Question 3

Insulin Sensitivity

Answer 3

decreased –> high blood sugar

Question 4

Cholesterol

Answer 4

Decreased HDL

Decreased lipoprotein lipase activity –> high cholesterol

Question 5

HR & BP during exercise

Answer 5

higher HR & BP response during submax exercise b/c not as efficient w/ stroke volume (not as good of stretch)

Question 6

Effects of training in Older individuals

• endurance
• body comp
• metabolic changes

Answer 6

endurance training produces similar results in older adults as in the young

• increased VO2 max by 10-40%
• decreased BP & HR
• increased BMD

Body comp - decrease weight and fat

Metabolic changes

• increased insulin sensitivity
• decreased cholesterol

Question 7

Effects of Aging on Muscle Strength

Answer 7

After age 50:

• mass declines 1-2% per year
• strength declines 1.5% per year

After age 60:

• strength can decrease up to 3% per year
• 65+ has 25% muscle loss
• 80+ has 30-50% muscle loss

the lower the muscle mass & strength the closer you get to reaching the disability threshold

Question 8

Sarcopenia

• what is it
• why does it happen
• primary factor
• clinical significance

Answer 8

aging disease that causes changes in body composition & function - loss of muscle mass & increase in body fat)

due to multifactorial components - disuse, inflammation, endocrine disorders, etc.

Muscle mass (not function) is the PRIMARY factor underyling age and gender related strength differences

Clinical significance:

• greater incidence of mortality after 40% loss of lean mass
• severe risk of mortality if ~60% below young adult average
• related to falls, decreased metabolism, increased fat, & decreased function

Question 9

Assessment of muscle mass

Answer 9

MRI, DEXA, computed axial tomography, bioelectrial impedence, or arthropometric estimation (skin folds, waist circumference, etc)

Question 10

Skeletal Muscle Index

Answer 10

ratio of appendicular lean mass relative to height in meters squared

• normalized muscle to frame size

Question 11

Talk Test

Answer 11

approximates ventilatory threshold
- point at which pulmonary ventilation becomes disproportionately high is respect to O2 consumption, anaerobic metabolism & lactic acid build up

aka an increase in RR can no longer meet demands of VO2

**when speech first becomes difficult, exercise intensity was almost exactly equivalent to ventilatory threshold

Question 12

Problem w/ APMHR

Answer 12

may not be valid, monitor intensity closely w/ RPE, talk test, and patient symptoms