L36 Exercise Physiology across the lifespan

Question 1

Outline and explain the effect of older age on VO2max

Answer 1

• Peak aerobic fitness is reduced with age

- Decrease in 1% per year after 30 years of sedentary behavior

Question 2

Explain how heart structure and function (systolic and diastolic) are altered in older individuals

Answer 2

• Thickening of the left ventricle wall
• Increases heart weight
• Increases chamber dimension
• Increases cardiomyocyte dimension
• Increases collagen in cross-linking

Question 3

Describe how exercise training can effect heart structure and diastolic function in older individuals

Answer 3

Left ventricle wall thickness is increased with age and exercise training. Diastolic function

Question 4

Explain how the regulation of the heart by the autonomic nervous system is altered with increased age

Answer 4

• Ageing reduces resting cardiac parasympathetic time and heart rate variability. HR variability is reduced with age.

Question 5

Provide a physiological rationale for the age-related reduction in maximal heart rate

Answer 5

220-age = max heart rate.

• Ageing reduces chronotropic (heart rate raising) effects of beta-adrenergic sympathetic stimulation

Question 6

Describe the effect of exercise training on resting autonomic control of the heart in older individuals

Answer 6

• Ageing reduces chronotropic (heart rate raising) effects of beta-adrenergic sympathetic stimulation
• Ageing reduces resting cardiac parasympathetic tine and heart rate variability. HR variability is reduced with age.

Question 7

Explain how age and exercise training effect arterial compliance and endothelial function

Answer 7

• Endothelial function is impaired with ageing – Using flow mediated dilation, we can see that as age increases, function decreases, drops off in men before women
• Endothelial dependent vasodilation is reduced in sedentary older subjects… but is increases with aerobic exercise training. – brachial artery flow-mediated dilation is impaired in older vs younger people.

Question 8

Describe how VO2max varies with childhood age in girls and boys when expressed in either absolute or relative terms

Answer 8

max O2 uptake increases with child growth
Similar until age 12 until it diverge due to body composition differences.
Vo2 max is maintained in boy through childhood but decreases in girls

Question 9

Explain how running economy is influenced by childhood age

Answer 9

O2 cost of walking and running is higher among children so less economic.
This may be due to children having less metabolic reserve

Question 10

Discuss the differences in anaerobic power between children, adolescents and adults

Answer 10

Kids - glycolytic capacity and anaerobic power is lower
Adolescents - sit somewhere in the middle
Adults - larger magnitude of increase in aerobic capacity than kids

Question 11

Explain how the hemodynamic responses to sub-maximal dynamic exercise differ in young children

Answer 11

During submaximal exercise younger children have a lower SV, compensated for by higher HR and oxygen extraction

Question 12

Describe how aerobic trainability differs between children and adults

Answer 12

Aerobic trainability is lower in children