Deck 5: Exercise Metabolism

Question 1

Energy to run a 40-yard dash comes

A) almost exclusively from the ATP-CP system.
B) exclusively from glycolysis.
C) almost exclusively from aerobic metabolism.
D) from a combination of aerobic/anaerobic metabolism, with most of the ATP being produced aerobically.

Answer 1

A

Question 2

The energy to perform long-term exercise (i.e., >20 minutes) comes primarily from

A) aerobic metabolism.
B) a combination of aerobic/anaerobic metabolism, with anaerobic metabolism producing the bulk of the ATP.
C) anaerobic metabolism.
D) anaerobic metabolism, with the ATP-PC system producing the bulk of the ATP.

Answer 2

A

Question 3

When calculating the RQ, protein is often ignored. Why?

A) because protein generally plays a small role as a substrate
B) because it is impossible to calculate the RQ for protein
C) because protein cannot be used as a substrate during exercise
D) because the RQ for protein is 0

Answer 3

A

Question 4

At rest, the O₂ consumption of a 70-kg young adult is approximately

A) 250 ml/min.
B) 0.25 L/min.
C) 3.5 ml/kg/min.
D) all of the above.

Question 5

Energy to run a maximal 400-meter race (i.e., 50 to 60 seconds) comes from

A) aerobic metabolism exclusively.
B) mostly aerobic metabolism with some anaerobic metabolism.
C) a combination of aerobic/anaerobic metabolism, with most of the ATP coming from anaerobic sources.
D) the ATP-CP system exclusively.

Question 6

Removal of lactic acid following a bout of intense exercise is

A) more rapid if the subject rests, compared to performing light exercise.
B) more rapid if the subject performs heavy exercise (>70% VO₂ max), compared to rest.
C) more rapid if the subject performs light exercise (~30% VO₂ max), compared to rest.
D) the same whether the subject rests or performs light exercise (~30% VO₂ max).

Question 7

The slow rise in oxygen uptake over time during high-intensity, prolonged exercise is due to

A) high blood levels of lactic acid.
B) rising body temperature.
C) rising blood levels of insulin.
D) the increased amount of work necessary to maintain exercise.

Question 8

Which of the following is true about VO₂ during exercise?

A) VO₂ increases linearly with work rate.
B) VO₂ is an indicator of glycolytic ATP production.
C) VO₂ drops sharply just prior to fatigue.
D) None of the above are true.

Question 9

Most of the carbohydrate (e.g., for a rested, well-fed athlete) used as a substrate during high-intensity exercise comes from

A) muscle glycogen stores.
B) blood glucose.
C) liver glycogen stores.
D) glycogen stored in fat cells.

Question 10

The process of breaking down triglycerides into free fatty acids and glycerol is called

A) beta oxidation.
B) glycogenolysis.
C) lipolysis.
D) lipogenesis.

Question 11

During the "rapid" portion of the oxygen debt (or EPOC), the excess VO₂ is due to

A) high body temperature.
B) gluconeogenesis.
C) restoration of muscle CP and blood and muscle oxygen stores.
D) elevated blood levels of epinephrine and norepinephrine.

Question 12

The primary fuel source during light-intensity (25% VO₂ max) exercise is

A) muscle glycogen.
B) blood glucose.
C) muscle triglycerides.
D) plasma FFA.

Question 13

Trained individuals have a lower oxygen deficit; this may be due to

A) having a lower VO₂ max.
B) having a greater reliance on anaerobic pathways.
C) the involvement of the ATP-CP energy system.
D) having a better developed aerobic bioenergetic capacity.

Question 14

The lactate threshold is defined as the work rate or oxygen uptake at which there is a systematic

A) rise in blood levels of lactic acid.
B) rise in aerobic metabolism.
C) decrease in blood lactic acid concentration.
D) rise in blood levels of lactate dehydrogenase.

Question 15

The first bioenergetic pathway to become active at the onset of exercise is

A) glycolysis.
B) the ATP-CP system.
C) the Krebs cycle.
D) the electron transport chain.

Question 16

The term oxygen deficit refers to the

A) lag in oxygen consumption at the beginning of exercise.
B) excess oxygen consumption during recovery from exercise.
C) amount of oxygen required to maintain a steady state during constant-load exercise.
D) amount of oxygen utilized by the ATP-PC system in the first few minutes of exercise.

Question 17

A respiratory quotient (RQ) of 0.95 during steady-state exercise is suggestive of a(n)

A) high rate of carbohydrate metabolism.
B) high rate of fat metabolism.
C) equal rate of fat/carbohydrate metabolism.
D) high rate of protein metabolism.

Question 18

The oxygen debt is generally higher following heavy exercise when compared with light exercise because heavy exercise

A) produces more lactic acid.
B) results in greater body heat gained, greater CP depleted, higher blood levels of epinephrine and norepinephrine, and greater depletion of blood and muscle oxygen stores.
C) results in a greater level of liver glycogen depletion.
D) is of shorter duration than light exercise.

Question 19

Which of the following factors may explain the rise in blood lactic acid at the lactate threshold?

A) an increased rate of lactate production
B) an increased rate of removal of lactic acid from the blood
C) both a and b
D) neither a nor b

Question 20

Depletion of carbohydrate stores during exercise influences fat metabolism by

A) increasing the amount of muscle lactic acid production.
B) reducing the level of Krebs cycle intermediates.
C) increasing the rate of fat metabolism.
D) reducing the rate of protein metabolism.

Question 21

The respiratory exchange ratio equals the respiratory quotient during short-term maximal exercise.

Question 22

Trained individuals usually produce less lactate than untrained individuals when making the transition from rest to steady-state exercise.

Question 23

The exercise intensity at which blood levels reach four millimoles per liter is termed the onset of blood lactate accumulation (OBLA).

Question 24

VO₂ max is determined by

A) the maximum ability of the cardiorespiratory system to deliver oxygen to the muscle.
B) the ability of the muscle to take up and use oxygen to produce ATP.
C) both a and b.
D) neither a nor b.

Question 25

Which of the following is true concerning the Cori Cycle?

A) It is one means of decreasing (metabolizing) accumulated lactate.
B) It may increase liver glycogen content.
C) It is supplied by glucose that has been removed from the blood.
D) It is a means by which glucose is synthesized from amino acids removed from the blood.

Question 26

The RQ for fat is

A) 0.70.
B) 0.82.
C) 0.85.
D) 1.00.

Question 27

The maximal rate of fat oxidation, FAT_max, typically occurs just before

A) VO?₂ max.
B) the LT.
C) oxygen deficit.
D) EPOC.

Question 28

The RER can rise above 1.00

A) during high-intensity exercise.
B) if VCO₂ > VO₂.
C) when the buffering of lactic acid stimulates ventilation to blow off CO₂.
D) when all of these occur.

Question 29

The drift upward of VO₂ during constant-load exercise in a hot environment is due to

A) rising blood levels of lactate.
B) decreasing blood levels of hormones.
C) increasing body temperature.
D) decreasing body temperature.

Question 30

After the first few minutes of constant-load, submaximal exercise, VO₂ reaches steady state, indicating that

A) the ATP demand is being met aerobically.
B) levels of lactic acid in the blood are very high.
C) the exercise can be continued indefinitely without fatigue.
D) the oxygen uptake is not sufficient to meet the ATP demand.

Question 31

Which of the following is true concerning VO₂ max?

A) It occurs at a lower intensity of exercise than the lactate threshold.
B) It is the maximal volume of oxygen that can be breathed into the lungs in one minute.
C) It is a valid measure of cardiovascular fitness.
D) It is the highest VO₂ achieved during prolonged steady-state exercise.

Question 32

Fat contains more energy per gram than carbohydrates; therefore, ATP can be produced more rapidly from fats than from carbohydrates.

Question 33

Lactic acid accumulation contributes to muscle fatigue during exercise and causes the muscle soreness that may occur 24-48 hours after exercising.

Question 34

The exercise intensity that promotes the greatest total grams of fat metabolized is

A) 20% of VO₂ max.
B) 50% of VO₂ max.
C) 80% of VO₂ max.
D) 100% of VO₂ max.

Question 35

The carbohydrate fuel source that becomes most important after 3-4 hours of moderate-intensity (~70% VO₂ max) exercise is

A) muscle glycogen.
B) blood glucose.
C) muscle triglycerides.
D) plasma FFA.

Question 36

The primary fuel source during high-intensity (85% VO₂ max) exercise is

A) muscle glycogen.
B) blood glucose.
C) muscle triglycerides.
D) plasma FFA.

Question 37

Which of the following conditions would result in a higher EPOC?

A) higher intensity of exercise
B) lower intensity of exercise
C) lower body temperature
D) lower blood lactate

Question 38

Lactate is formed and accumulates when the rate of glycolytic production of pyruvate and NADH exceeds the rate at which these products are shuttled into the mitochondria.

Question 39

The progressive increase in the percent energy from carbohydrates and a decrease in the percent energy from fat is called the

A) substrate shift phenomenon.
B) RQ effect.
C) crossover concept.
D) glycolytic surge.

Question 40

During moderate-intensity (65% VO₂ max) exercise, the percent of ATP derived from carbohydrates is ___________ the percent ATP from fats.

A) less than
B) equal to
C) greater than