1
Q
Using the Fick equation, what two physiological changes can increase VO₂ during exercise?
A
Both cardiac output and increased tissue extraction
2
Q
During heavy exercise, which changes the most?
A
CvO2
3
Q
What is the primary reason venous O₂ saturation drops during exercise?
A
Muscles extract more O₂
4
Q
The Bohr effect helps exercising muscle by:
A
Increasing O₂ unloading at the muscle
5
Q
A widened a-v O₂ difference means:
A
Muscles are extracting more oxygen
6
Q
After endurance training, which variable does not change at maximal exercise?
A
HRmax
7
Q
At the same submax workload before and after training, what is true?
A
HR is lower after training
8
Q
Which factor primarily explains why men have higher VO₂max than women?
A
Higher hemoglobin & larger cardiac output
9
Q
With aging, which change most directly lowers VO₂max?
A
Decreased maximal heart rate
10
Q
Training increases lactate threshold by:
A
Increasing mitochondrial efficiency & lactate clearance
11
Q
If a person has the same cardiac output at a given submax workload before and after training, but their HR is lower, what must have increased?
A
Stroke volume
12
Q
Why does oxygen deficit occur at the onset of exercise?
A
Aerobic metabolism takes time to activate
13
Q
Which factor would increase oxygen deficit?
A
Slow mitochondrial activation
14
Q
Which of the following is part of the rapid component of EPOC?
A
PCr replenishment
15
Q
Critical power represents:
A
The highest power output that can be sustained aerobically
16
Q
PCr resynthesis after exercise depends heavily on:
A
Mitochondrial oxidative capacity
17
Q
RER = 1.0 indicates:
A
100% carbohydrate use
18
Q
Why can RER exceed 1.0 during high-intensity exercise?
A
Increased bicarbonate buffering of H⁺
19
Q
The Gas Exchange Threshold (GET) is identified when:
A
VCO₂ increases disproportionately relative to VO₂
20
Q
The Respiratory Compensation Point (RCP) occurs when:
A
VE increases faster than VCO₂ due to metabolic acidosis
21
Q
Below lactate threshold, CO₂ in expired air comes from:
A
Carbohydrate metabolism and Buffering of H⁺
22
Q
Above lactate threshold, additional CO₂ comes from:
A
H⁺ + bicarbonate buffering
23
Q
A rising VE/VO₂ with stable VE/VCO₂ indicates:
A
You’ve reached the Gas Exchange Threshold
24
Q
The Gas Exchange Threshold occurs because:
A
Non-metabolic CO₂ appears from H⁺ buffering
25
On a VCO₂ vs VO₂ graph, GET is identified when:
The slope becomes steeper
26
Which ventilatory ratio rises FIRST at GET?
VE/VO₂
27
RCP represents:
The onset of hyperventilation due to falling pH
28
Stable VE/VCO₂ with rising VE/VO₂ indicates:
RCP (VT2)
29
Respiratory compensation begins when:
PaCO₂ drops due to hyperventilation
30
During exercise, the primary mechanism of heat loss is:
Evaporation
31
Why does exercise performance decrease in high heat?
Skin blood flow competes with muscle blood flow
32
Dehydration reduces stroke volume primarily because:
Plasma volume decreases
33
Heat acclimation causes all EXCEPT:
Higher core temperature during exercise
34
In cold environments, FFA use decreases because:
Vasoconstriction limits adipose tissue blood flow
35
Cold water immersion after strength training:
Impairs long-term strength gains
36
Heat loss in water compared to air is:
25x faster
37
What is the primary reason arterial oxygen saturation decreases at altitude?
Lower barometric pressure reducing PO₂ gradient
38
A person exercising at the same workload at altitude will:
Perceive exercise as harder
39
Acute exposure to altitude triggers:
Hyperventilation and increased sympathetic activity
40
Chronic adaptation to altitude includes:
Increased EPO and RBC production
41
Acute mountain sickness is caused by:
Low arterial oxygen pressure
42
The "Live High, Train Low" method works because:
Living high increases RBC mass while training low allows higher training intensity
43
In heart transplanted patients, what is a significant factor that leads to decrements in maximal oxygen consumption during exercise?
Decrease in cardiac output due to inadequate heart rate response.
44
In heart transplanted patients, the increase in heart rate during exercise depends mostly on:
Epinephrine release from the adrenals.
45
During exercise, patients with heart failure with reduced ejection fraction (HFrEF) experience several physiological limitations compared to healthy individuals. Which of the following best describes the main consequence of HFrEF during exercise?
Decreased cardiac output leading to early fatigue and reduced exercise tolerance.
46
Heart transplant survivors are usually considered "anemic" due to the use of immunosuppressants that decrease the concentration of hemoglobin in blood. A study showed that heart transplant survivors have about 100 g/L of hemoglobin in their blood, compared with healthy individuals, who have about 150 g/L. How much does this difference affect the concentration of oxygen in the arterial blood (CaO2)?
Heart transplant survivors have about 35% lower CaO2 than healthy individuals.
47
Although heart transplant patients have significantly lower V'O2max (~14 mL/kg/min), it is proven that endurance exercise training restores the V'O2max to healthy levels (~40 mL/kg/min).
False
48
A study was conducted in rats treated with cyclosporin A for 3 weeks, a known immunosuppressant commonly used by heart transplant recipients. After 3 weeks of treatment, the scientists collected the muscles used for running for analysis. How do these results explain the changes in exercise tolerance detected in heart transplant patients compared to healthy individuals?
The use of immunosuppressants reduces the proportion of more fatigue-resistant muscle fibers and increases the proportion of less fatigue-resistant fibers, which directly produces a deficit in muscle oxygen utilization capacity and contributes to exercise intolerance in heart transplant patients.
49
During the development of heart failure with reduced ejection fraction (HFrEF), V'O2max decays faster over the years compared to healthy individuals due to decrements in stroke volume divided by the end-diastolic volume.
True
50
Maximal oxygen uptake (V'O2max) during exercise declines with aging. What is the average decay in V'O2max per decade mentioned by Dr. Kolkhorst in his presentation?
10% in sedentary subjects and 6% in trained subjects
51
Individuals with heart failure with reduced ejection fraction (HFrEF) have significant decreases in stroke volume. The figure below shows the stroke volume as a function of the end-diastolic volume in two individuals, a HFrEF patient and a healthy individual. Which one is the HFrEF patient, and why was it different than the healthy individual?
Individual A. For the same given end-diastolic volume, stroke volume was lower in A than in B due to greater cardiac fibrosis and a thinner ventricular wall, leading to weaker ventricles.
52
A study was performed on patients with Heart Failure with preserved Ejection Fraction (HFpEF) and Heart Failure with reduced Ejection Fraction (HFrEF). Hemodynamic data on cardiovascular performance were obtained during rest and treadmill exercise, and results are shown below: Dr. Kolkhorst mentioned in his talk that the average ejection fraction in healthy individuals is about 60%. Dr. Kolkhorst was a patient with one of these two conditions. Which patient had a different condition from Dr. Kolkhorst?
Subject 2 because they had an EF of 56% that increased with exercise
53
The table below shows the rating scale for aerobic fitness according to the V'O2max values obtained from a large group of people. How would you rate the aerobic fitness of a 90-kg, 41-year-old male with a V'O2max of 3.6 L/min?
Fair
54
How would you rate the aerobic fitness of a 50-kg, 41-year-old female, who at her V'O2max intensity at sea level (Inspired O2 = 20%), the fractional concentration of O2 in the expired air (FEO2) was 0.15, and minute ventilation (V'E) was 42 L/min?
Excellent
55
Compared to resting, the rate of oxygen consumption (VO2) increases with exercise intensity because__________:
there is an increase in oxygen extraction from the locomotor and respiratory muscles and there is an increase in cardiac end-diastolic volume.
56
What directly increases arterial-venous oxygen difference during exercise?
Mitochondria in the exercising muscles take up and use oxygen faster.
57
In hot environments, blood flow is partially redistributed from working muscles to ___________.
Skin
58
During the first 48 h of high-altitude exposure, what is the sensory component that primarily produces the cardiorespiratory changes detected at this environment?
arterial PO2 chemoreceptors
59
What is the primary mechanism for heat loss during exercise?
Sweat evaporation
60
During maximal exercise, the oxygen saturation of blood reaching out to working muscles (___) is _____ the arterial oxygen saturation of blood at rest. A. SaO2; similar to B. SaO2; less than C. SaO2; more than D. SvO2; similar to E. SvO2; less than F. SvO2; more than
SaO2; similar to
61
During maximal exercise, the oxygen saturation of blood leaving working muscles (____) is _____ the oxygen saturation of blood reaching muscles.
SvO2; less than
62
Which of the following physiological adaptations would most directly increase VO2max following endurance training?
Enhanced stroke volume and maximal cardiac output leading to greater oxygen delivery.
63
During an incremental exercise test below VO2max, which of the following statements best explains the metabolic contribution to energy production?
Both oxidative and non-oxidative metabolism contribute to ATP resynthesis at all intensities, with their relative contributions shifting as intensity increases
64
Which of the following best explains the oxygen deficit observed at the onset of exercise?
The delay in achieving steady-state VO2 due to the time required for oxidative metabolism to fully activate.
65
Which of the following would increase the magnitude of oxygen deficit during the onset of exercise?
Beginning exercise abruptly at a higher work rate without prior priming exercise
66
Which of the following best explains why oxygen consumption remains elevated after exercise (i.e., EPOC)?
To repay the oxygen debt by restoring phosphocreatine and glycogen stores and clearing lactate
67
During very high-intensity exercise, the Respiratory Exchange Ratio (RER) can exceed 1.0 (sometimes reaching up to 1.3). What is the main physiological reason for this increase?
Blood bicarbonate buffering of excess hydrogen ions, producing extra CO₂
68
An individual performed two separate sessions of exercise in different days, a shorter session that took about 10 min to complete (Exercise A) and a more prolonged one that last about 40 min (Exercise B). In both sessions, inspired and expired gas analyses were performed, which allowed the calculation of the Respiratory Exchange Ratio (RER) before and during exercise. Data from these two sessions are shown below.: In exercise B, the rate of oxygen uptake was greater than the rate of carbon dioxide production during the entire period of exercise
69
During treadmill velocities below the lactate threshold, what is(are) the source(s) of CO2 in expired air ?
Carbohydrate metabolism and fat metabolism
70
During treadmill velocities above the lactate threshold, what is(are) the source(s) of CO2 in expired air ?
All of the above
71
At Pikes Peak, your PAO2 would be ~45 mm Hg. At this altitude, how much of the hemoglobin leaving your lungs would be saturated with oxygen?
80%
72
A 28-year-old mountaineer travels from sea level to 3,500 meters and performs a submaximal exercise test the following morning. Compared with her sea-level performance, she reaches her ventilatory threshold earlier and reports higher perceived exertion despite working at the same absolute workload. Which physiological change most directly explains her reduced submaximal exercise capacity at high altitude?
Lower arterial oxygen saturation reducing oxygen delivery to muscles.
73
A 40-year-old trail runner arrives at 2,800 meters and immediately begins a training run. Within minutes, he experiences increased ventilation, lightheadedness, and a noticeable rise in heart rate during exercise. Which acute response best accounts for his increased resting and exercise ventilation at altitude?
Hypoxic stimulation of peripheral chemoreceptors increasing ventilatory drive
74
An individual living at sea level has a hemoglobin concentration of 14.5 g/dL and an arterial oxygen saturation (SaO₂) of 97%. After ascending to an altitude of 4,000 m, their SaO₂ drops to 80%. Following 3 months of acclimatization at that altitude, the individual's hemoglobin concentration increases to 16.5 g/dL. Assuming that SaO2 did not change after 3 months of acclimation, what is the percentage change in arterial oxygen content (CaO₂) at high altitude after the 3-month acclimation?
+14%
SDSU ENS 304
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