chapter 9: circulatory responses to exercise

Question 1

why does heart rate and blood pressure change during exercise? (what do these changes reflect)

Answer 1

1. type and intensity
2. duration
3. environmental conditions

Question 2

pressure and volume response to exercise

Answer 2

• intensity dependent increase in systolic BP
• increased stroke volume (increase EDV and decrease ESV)
• increased cardiac contractility (shortened isovolumetric contraction and relaxation phase)

Question 3

emotional influence on HR and BP

Answer 3

• at submax it will increase HR and BP compared to an emotionally neutral environment (caused by increase SANS)
• at maximal high emotions increased PRE-exercise HR and BP but not peak HR or BP during exercise

Question 4

transition from rest to exercise - what happens when you first change to exercise

Answer 4

• rapid increase in HR, SV, and CO.
  HR and CO will increase in the first second after muscular contraction

Question 5

if work rate is constant and below lactate threshold when will HR, SV, and CO be met

Answer 5

2-3 minutes

Question 6

is the slope of heart rate decay following exercise different between trained and untrained individuals

Answer 6

generally the same

Question 7

what factors delay fall in HR

Answer 7

• prolonged session
• hot/humid environment
• elevated body temperature

Question 8

what physiological responses ensure ATP is available for muscular contraction during exercise

Answer 8

HR & CO are directly proportional to oxygen uptake and more blood flow to muscles

Question 9

what is double product ( rate-pressure product)

Answer 9

estimation of increased metabolic demand placed on HR during exercise (HR x systolic BP)

Question 10

what is the result of increased exercise intensity on HR and systolic BP

Answer 10

increased

Question 11

why is HR and BP higher during an arm workout compared to leg

Answer 11

1. greater sympathetic outflow to HR
2. increased BP from vasoconstriction in blood vessels inactive muscle groups (causes increased peripheral resistance)

Question 12

what factors impact interval recovery response during intermittent exercise (interval training)

Answer 12

1. level of fitness
2. environmental conditions
3. duration
4. intensity

Question 13

what happens to HR, SV, and CO during prolonged exercise?

Answer 13

CO is maintained (but SV declines to HR must increase to sustain)

Question 14

what causes cardiovascular drift (increased HR and decreased SV during prolonged exercise)

Answer 14

1. rising body temp on dehydration and reduction in plasma volume

lower plasma volume -> decreased venous return -> decreased preload => decreased SV