Mid: Pre lab quizzes

Question 1

The reason that mitochondria cannot fully exploit their oxidative ability is a result of the limitation on O2 delivery imposed by the central cardiovascular system.
(true/false)

Answer 1

true

Question 2

The normal range of VO2max values (L·min-1) observed in sedentary and trained men and women of the same age is due principally to variation in what factor?

Answer 2

stroke volume

Question 3

is there an upper limit to oxygen uptake?

Answer 3

yes

Question 4

Not all subjects show a plateau in VO2 at the end of a graded exercise test (GXT), when graphed against work intensity. It has repeatedly been shown that about what % of subjects do not demonstrate a plateau when stressed to maximal effort?

Answer 4

50%

Question 5

Regarding the pulmonary system as a factor limiting exercise performance, it is generally accepted that in the average individual exercising at sea level, the lungs perform their job of saturating the arterial blood with O2 extremely well
(true or false)

Answer 5

true

Question 6

In a 20-minute all-out performance, approximately how much ATP production is derived from aerobic processes?

Answer 6

90%

Question 7

The term “maximal oxygen uptake” was coined and defined by Hill et al. and Herbst in what decade

Answer 7

1920

Question 8

what is the primary criterion for have reached true VO2 max

Answer 8

The VO2 fails to increase when the workload is increased-yielding a plateau in the VO2 and this is observable in only about 50% of healthy adult subjects. (do we know by how much?)

Question 9

Because not all participants achieve a plateau in VO2max with increasing workloads, it is recommended that secondary criteria be applied to verify maximal effort. which are?

Answer 9

respiratory exchange ratio >1.15 and blood lactic acid level of >8-9 mM

Question 10

Reinfusion of 900–1,350 mL blood elevates the oxygen carrying capacity of the blood. This procedure has been shown to increase VO2max by what % in well designed, double-blind studies

Answer 10

4-9%

Question 11

A noninvasive technique that is commonly used to estimate the percent contribution of carbohydrate or fat to energy metabolism during exercise is the ratio of the volume of carbon dioxide produced (VCO2) to the volume of oxygen consumed (VO2). What is the common three word definition for this concept?

Answer 11

respiratory exchange ratio

Question 12

Current evidence shows that only about ____% of the oxygen debt is used to convert the lactate produced during exercise to glucose (gluconeogenesis).

Answer 12

20%

Question 13

During high-intensity, short term exercise (i.e. 2 to 20 seconds), the muscle ATP production is dominated by what energy system(s)?

Answer 13

ATP-PC

Question 14

The term oxygen deficit applies to the lag in oxygen uptake at the beginning of exercise. Specifically, the oxygen deficit is defined as

Answer 14

the difference between oxygen uptake in the first few minutes of exercise and an equal time period after steady state has been obtained

Question 15

In human muscle with adequate glycogen stores, submaximal exercise (i.e. 70 % VO2 max) results in a __________ increase (above resting values) in the number of Krebs-cycle intermediates.

Answer 15

ninefold

Question 16

High-intensity events lasting longer that 45 seconds use what energy system(s)

Answer 16

ATP-PC, anaerobic glycolysis, and aerobic with a 50%/50% split between aerobic and anaerobic

Question 17

What one word answer is a common cause of invalidating the use of R to estimate which fuel is being consumed?

Answer 17

hyperventilation

Question 18

Blood lactate levels following strenuous exercise remain elevated for at least ___ minutes when there is no exercise in recovery. Removal is _________ when light exercise is used in recovery.

Answer 18

40 min, faster

Question 19

According to Figure 15 of Bassett & Howley (2000), training causes an increase in maximal oxygen uptake and with training a subject is also able to tax a greater percentage of their maximal oxygen uptake during prolonged work. (true/false)

Answer 19

true

Question 20

Decreasing blood pH ________ tissue oxygen unloading at the tissue level.

Answer 20

increases

Question 21

The term ventilatory threshold (Tvent) describes the point where pulmonary ventilation is tightly linked to oxygen demand at the cellular level.
(true.false)

Answer 21

false

Question 22

The term “running economy” is used to express the oxygen uptake needed to run at a given velocity. This can be shown by plotting oxygen uptake (mL·kg-1·min-1) versus running velocity (m·min-1) or by simply expressing economy as the energy required per unit mass to cover a horizontal distance (mL O2·kg-1·km-1).(true/false)

Answer 22

true

Question 23

The following is an important intermediate step in the reversible conversion of CO2+H2O to H2CO3 (carbonic acid).

Answer 23

carbonic anhydrase

Question 24

An early definition of anaerobic threshold is “the point of a systematic rise in blood lactate during incremental exercise”.

Answer 24

true

Question 25

In blood, about _____% of O2 is bound to hemoglobin, compared to only about _____% for CO2.

Answer 25

99%, 20%

Question 26

The term lactate threshold describes the highest oxygen consumption or exercise intensity achieved with less than a ______ mM increase in blood lactate concentration above the pre-exercise level, whereas as the onset of blood lactate accumulation (OBLA) signifies when blood lactate concentration systematically increases to ______ mM.

Answer 26

1.0, 4.0

Question 27

According to the ACSM 2007 article, body weight changes can reflect sweat losses during exercise and can be used to calculate individual fluid replacement needs for specific exercise and environmental conditions.
(true/false)

Answer 27

true

Question 28

During exercise in a hot environment, three major changes occur in muscle metabolism that contribute to muscle fatigue; list and explain these changes.

Answer 28

1. Increased Radical Production
2. Decreased muscle pH
3. Muscle glycogen depletion

Question 29

exertional heat stroke at what temp

Answer 29

> 40.5

Question 30

According to the ACSM 2007 article, individuals often achieve sweating rates from ____to____ L·h−

Answer 30

0.5-2

Question 31

The heat acclimation process is the best protection against exertional heatstroke and heat exhaustion. Heat acclimation involving exercise in the heat for 10-14 days accomplish the following five favourable adaptations

Answer 31

1. Increases in plasma volume, skin blood flow, and sweating
2. Increase in VO2 max, cardiac output max, and power output and lactate threshold
3. Decrease in body temp and heart rate response to sub maximal exercise
4. Decreased salt loss in sweat and chance of sodium depletion
5. Increase in aerobic exercise performance

Question 32

sweat electrolyte concentrations:

sodium , potassium, calcium, magnesium, chloride

Answer 32

Sodium ~35 mEq·L−1 (range 10-70 mEq·L−1)
Potassium averages 5 mEq·L−1 (range 3-15 mEq·L−1)
Calcium averages 1 mEq·L−1 (range 0.3-2 mEq·L−1)
Magnesium average 0.8 mEq·L−1 (range 0.2-1.5 mEq·L−1)
Chloride averages 30 mEq·L−1 (range 5-60 mEq·L−1