Adaptations Related to Exercise and Aging

What are the effects of aging on exercise?

loss of muscle mass

increased body fat composition

arterial stiffening

decreased insulin sensitivity

chest wall stiffening

decreased daily physical activity

decreased ability to handle thermal stress

What are the effects of aging on the cardiovascular system?

VO2max decline ~10% per decade

heart effects

What causes the decline of VO2max?

decrease in maximal cardiac output (max HR)

decreased maximal SV

decrease in maximal arteriovenous oxygen difference

What are the heart effects from aging?

increased LV wall thickness and stiffness

decreased contractility

decreased sensitivity to catecholamines

increased SBP

impaired vasodilation

What is the role of training on the cardiovascular system?

only lose 5% of VO2max per decade

still able to increase VO2max with training

training blunts age-related adaptations of cardiac muscle

increased vasoconstriction in inactive muscle during exercise

exercise can really slow the chronological aging!!!

increased exercise tolerance leads to…

increased independence!

What are the effects of aging on the pulmonary system?

decreased elastic recoil

increased chest wall stiffness

decreased diffusion area

decreased resting paO2 5-10 mmHg

increased submax minute ventilation

dyspnea more common

increased work of breathing - respiratory muscles use greater % VO2

some may desaturate during workout

increased pulmonary artery pressure may induce pulmonary edema

What are the effects of exercise on the pulmonary system?

decreased submax minute ventilation increases efficiency, removes ventilatory limitation to exercise, and decreases dyspnea

What is sarcopenia?

age-related loss of muscle mass

decreased mass and loss of strength

How does aging impact skeletal muscle

selective atrophy of type II fibers

loss of alpha motor neurons in spinal cord

slower activation of motor units

increased stiffness of connective tissue

What are the functional consequences of sarcopenia?

impaired balance

decreased ability to perform daily tasks

decreased mobility

risk for hospitalization

loss of ability to live independently

lower self-esteem

glucose intolerance

hip fracture risk

Resistance training increases strength in older adults by how much?

30% to > 100% in very weak persons - can equal reversing 2 decades of age

Resistance training increases muscular endurance in older adults by how much?

300%

Resistance training increases muscle size in older adults by how much?

~ 15%

What effects does resistance training have on older adults?

normalize blood pressure in high normal range

reduce insulin resistance

decrease total and intra-abdominal fat

increase resting metabolism

prevent loss of BMD

reduce fall risk

reduce pain and improve function in arthritis

How does resistance training impact the neural component?

increases motor unit recruitment and firing rate - explains why strength gains are so much larger than muscle size gains

How does resistance training impact the cognitive component?

physical activity/exercise shown to help preserve cognitive function

strength linked to cognitive function

may slow decline due to progressive diseases

likely stimulates new neural connections

improved blood flow to brain

How can a visual impairment impact exercise?

important to adapt to lighting, visual cues in exercise/fitness facilities

What are some considerations for exercise in older adults?

comorbidities

impairments in hearing or vision

cognitive impairments

exercise tests can range from standard treadmill or bike to functional batteries such as the PPT

What level of resistance training do you need to do to see growth in muscles?

at least 70% 1RM!!