Wk11: Ageing and Inactivity

Question 1

What age are men and women at their strongest? Why is that? What happens after that age?

Answer 1

• 20 to 40
• muscle cross-sectional area is at its largest.
• concentric strength of most muscle groups declines, slowly at first and then more rapidly after middle age.

Question 2

What other reasons does strength loss increase during middle age?

Answer 2

• weight loss

- increase in chronic diseases, such as stroke, diabetes, arthritis and coronary heart disease.

Question 3

What decreases faster, power or strength?

Answer 3

power

Question 4

What does strength loss in the elderly directly relate to?

Answer 4

limited mobility and fitness stars and potential for increased incidence of accidents from muscle weakness, fatigue and poor balance.

Question 5

What is motor unit remodelling?

Answer 5

represents a normal , continuous process that involves motor endplate repair and reconstruction.

Question 6

What happens to motor units during older age?

Answer 6

motor unit remodelling deteriorates causing denervation muscle atrophy (degeneration of muscle fibres).

Question 7

What age does physiologic and performance capabilities usually decline?

Answer 7

after age of 30

Question 8

what is the effect of older age people doing regular physical activity?

Answer 8

higher levels of functional capacity (mainly cardiovascular and muscular function).

Question 9

Biologic ageing relates to changes in which 3 hormonal systems?

Answer 9

hypothalamic-pituritary-gonadal axis

adrenal cortex

growth hormone-insulin

Question 10

What 4 factors are important when evaluating physiologic and performance differences between children and adults?

Answer 10

1. exercise economy
2. FFM
3. anaerobic power
4. anabolic hormone levels.

Question 11

What is the primary cause of age-associated reduction in muscle strength between ages 25 and 80?

Answer 11

40 to 50% reduction in muscle mass from a loss of motor units and muscle finer atrophy.

Question 12

What is the effect of resistance training in the elderly?

Answer 12

stimulates protein synthesis and retention, which slows down the inevitable loss of muscle mass and strength with raging.

Question 13

What is the effect of resistance training on plasticity?

Answer 13

plasticity exists in the physiologic, structural and performance characteristics among older individuals and that enables rapid strength improvements with training into the 9th decade of life.

Question 14

What mechanisms explain how middle-aged elderly persons respond to resistance training?

Answer 14

• enhanced motor recruitment
• innervation patterns
• muscular hypertrophy

Question 15

What are the effects of ageing on CNS function?

Answer 15

a nearly 40% decline in the no. of spinal cord axons

a 10% decline in nerve conduction velocity

• this affects the time to detect a stimulus and process the information to produce the response.

Question 16

What is the effect of physical activity on neuromuscular function?

Answer 16

• affects neuromuscular function positively at any age and possibly slows the age-related decline in cognitive performance associated with speed of information processing.

Question 17

What is the effect of ageing on endocrine function?

Answer 17

• impaired glucose tolerance leading to type 2 diabetes. - caused by poor diet, inadequate PA, increased body fat.
• more inactive thyroid - affects metabolic function including decreased metabolic rate, glucose metabolism and protein synthesis.

Question 18

What are the effects of ageing on pulmonary function?

Answer 18

• deterioration in static and dynamic lung function
• pulmonary ventilation and gas exchange kinetics during the transition from rest to sub maximal exercise slows substantially.

Question 19

What happens to VO2max with aging?

Answer 19

decline approximately 1% each year in adult men and women (almost twice as fast in those who are sedentary). Physically active older men and women maintain aerobic power more than sedentary peers at any age.

Question 20

What factors, other than PA, cause a decline in VO2 max?

Answer 20

• hereditary
• increase in body fat
• decrease in muscle mass
• decrease in muscles oxidative function from reduced synthesis of mitochondrial and other proteins.

Question 21

What are the effects of ageing on heart rate?

Answer 21

• decline in maximum exercise heart rate due to reduced medullary outflow of sympathetic activity.

Question 22

What is the effect of ageing on cardiac output?

Answer 22

maximum cardiac output decreases with age in trained and untrained men and women bc of a lower maximum heart rate and stroke volume.

Question 23

How do healthy individuals compensate for diminished heart rate?

Answer 23

increased cardiac filling (end diastolic volume), which subsequently increases SV by the Frank-Sterling Mechanism.

Question 24

What is the affect of ageing on large artery compliance?

Answer 24

compliance of large arteries in the cardiothoracic circulation declines with age from change in arterial wall’s structural and non-structural properties.

• cannot stretch and recall, causing stiffening leading to hypertension, stroke, etc. - PA reduces stiffening.

Question 25

What is the effect of sedentary lifestyle on functional capacity?

Answer 25

sedentary lifestyle causes losses in functional capacity at least as great as ageing itself. Regular exercise improves physiologic function at any age; initial fitness, genetics, and type and amount of training control the magnitude of change.

Question 26

The effects of ageing on body composition and FFM?

Answer 26

• older athletes average 20% less body fat and 20% more FFM than nonathletic peers.
• this suggests that habitual PA confers some protection from the negative effects of ageing on body composition.

Question 27

What is better for health? vigorous activity in early life or a more physically active lifestyle throughout life?

Answer 27

physically active lifestyle throughout life

Question 28

What are the benefits of regular moderate exercise?

Answer 28

• decreases the chance/effects of coronary heart disease risks.
• a sedentary person runs almost twice the risk of developing heart disease as the most active individuals.