Lab 8: Graded Exercise Testing

Question 1

best indicator of overall cardio respiratory function

Answer 1

VO2 max

Question 2

potential reasons for using a graded exercise test

Answer 2

can be used for a young, healthy individual to measure changes in cardio respiratory function before and after a training program

could also be used for a 60 yo with multiple risk factors as a diagnostic for heart disease

Question 3

common measurements for all graded exercise procedures

Answer 3

cardiac electrical conduction through 12-lead ECGs, ratings of perceived exertion (RPE), oxygen consumption, and blood pressure

Question 4

one of the most valuable and convenient indicators of cardiovascular health

Answer 4

blood pressure measurements

Question 5

what is systolic blood pressure

Answer 5

pressure in the arteries when the heart contracts

Question 6

what is diastolic blood pressure

Answer 6

pressure in arteries when the heart is filling between beats

Question 7

what is the pulse pressure

Answer 7

difference between systolic and diastolic blood pressure

Question 8

healthy blood pressure is defined as:

Answer 8

less than 120/80 mm Hg

Question 9

how does blood pressure change with age?

Answer 9

rises steadily with age due to arterial stiffness and plaque buildup

Question 10

what is the mean arterial pressure

Answer 10

average pressure in the arteries during a cardiac cycle

Question 11

why is MAP important?

Answer 11

it determines the rate of blood flow through the vasculature

Question 12

equation for MAP

Answer 12

MAP = dBP + 1/3PP

Question 13

why is MAP calculated using 1/3 of the pulse pressure? how does this affect MAP measurements during exercise?

Answer 13

because the heart is in diastole for two thirds of the cardiac cycle at rest; MAP measurement loses accuracy during exercise because the heart is in systole for a relatively greater amount of time compared to rest

Question 14

how is MAP determined during exercise?

Answer 14

by using cardiac output (Q) and total peripheral resistance (TPR)

(MAP = Q x TPR)

Question 15

what is total peripheral resistance (TPR)?

Answer 15

sum of resistance to blood flow in the vasculature

Question 16

why does blood pressure increase during exercise?

Answer 16

because of large increase in cardiac output

Question 17

factors that contribute to increased cardiac output during exercise?

Answer 17

elevated heart rate and increased ventricular contractility (due to sympathetic activity) and increased venous return

Question 18

what is MAP also referred to?

Answer 18

afterload: the barrier to the ejection of blood from the ventricles

Question 19

stroke volume must increase more than ___ to pump blood to the body

Answer 19

blood pressure

Question 20

what helps attenuate increases in afterload during exercise?

Answer 20

vasodilation of arterioles supplying blood to active muscles

Question 21

how do systolic and diastolic blood pressure change during exercise?

Answer 21

systolic blood pressure increases due to increased cardiac output and diastolic blood pressure does not change (or may decrease slightly) due to vasodilation

Question 22

how does aerobic exercise training affect blood pressure?

Answer 22

decrease resting and submaximal exercise blood pressure

Question 23

how does aerobic training affect heart rate?

Answer 23

decreased resting and submaximal heart rate

Question 24

how does aerobic training affect TPR?

Answer 24

vascular tone (TPR) is diminished through a variety of factors

Question 25

do diastolic, systolic, and MAP change during max exercise?

Answer 25

systolic and MAP typically do not change at max, but diastolic can

Question 26

how does aerobic training indirectly affect blood pressure via weight loss?

Answer 26

weight loss has favorable influences on blood pressure

Question 27

besides directly evaluating for cardiorespiratory fitness, why else might a GXT be performed?

Answer 27

extending the medical history and physical, evaluating exertional discomfort, evaluating the presence of hidden coronary artery disease, stratifying risk in patients with known cardiovascular disease, and prescribing exercise

Question 28

prior to a GXT, how are subjects classified?

Answer 28

into three different risk categories based on age, known disease, and risk factors

Question 29

low risk individuals:

Answer 29

do not need physician supervision during a GXT

Question 30

moderate risk individuals:

Answer 30

are recommended to undergo a medical exam prior to maximal exercise testing

Question 31

high risk individuals:

Answer 31

are recommended to undergo a medical exam before max exercise testing and must be supervised by a physician

Question 32

when is a GXT stopped?

Answer 32

a predetermined point (based on percent of HR max), volitional exhaustion, or chest pain/breathlessness

Question 33

how does heart rate change during a GXT? stroke volume?

Answer 33

heart rate increases linearly until max, stroke volume increase linearly until a certain intensity where it plateaus

Question 34

when does SV plateau in untrained individuals? trained individuals?

Answer 34

untrained: 50% VO2 max
trained: much greater intensities, maybe not at all

Question 35

how does cardiac output change over a GXT?

Answer 35

increases greatly at first, then less as stroke volume plateaus

Question 36

what affect does altered action potential duration, conduction velocity, and contractile velocity (all due to increased HR) have on a normal ECG?

Answer 36

reduced RR intervals, minor QRS and P wave changes

Question 37

cardiovascular dysfunctions not apparent at rest that can present during exercise

Answer 37

arrhythmias, conduction disturbances, and myocardial ischemia (reduced blood flow)

Question 38

most common sign of myocardial ischemia during a GXT

Answer 38

ST segment depression

Question 39

describe the procedure generally

Answer 39

two groups: one performs the GXT and the other does BP measurements, then switch

BP measurements: take 2 seated BP and 2 standing BP measurements

GXT: measure BP in the exercise posture, determine speed on treadmill that elicits HR of 70% max (speed constant for duration of test), increase treadmill grade 2% every 2 minutes (do not exceed 10% —> if subject completes 2 mins at 10%, increase speed by 1 mph every 2 mins) record HR every minute, record BP and RPE during the second min of each stage, stop when subject reaches exhaustion or termination criteria is met, record HR and BP immediately post exercise and then every minute until stabilized near baseline level