Deck 20: Factors Affecting Performance

Question 1

What is the primary source of ATP production in ultra short-term (high intensity)exercise performances (i.e. ,exercise lasting less than 10 seconds)?

A)oxidative phosphorylation
B)phosphocreatine (i.e. ,ATP-PC system)
C)equal ATP production is derived from glycolysis and oxidative phosphorylation
D)equal ATP production is derived from phosphocreatine and oxidative phosphorylation

Answer 1

B

Question 2

Which of the following durations of exercise would environmental factors play the largest role in determining performance?

A)events <10 seconds duration
B)events 10-180 seconds duration
C)events lasting 3-20 minutes duration
D)events lasting 1-4 hours

Answer 2

D

Question 3

Experiments have shown that following a series of voluntary contractions to produce skeletal muscle fatigue,electrical stimulation of the "fatigued" muscle group results in an increase in the maximal voluntary force production.This experiment suggests that:

A)exercise-induced muscle fatigue results from peripheral factors located within the muscle.
B)exercise-induced muscle fatigue results from peripheral factors located at the neuromuscular junction.
C)the upper limit of voluntary strength is psychologically set and that the central nervous system can limit performance.
D)None of the above answers are correct

Answer 3

C

Question 4

A high H⁺ concentration can contribute to fatigue by

A)reducing the force generated per cross-bridge.
B)interfering with Ca⁺⁺ binding to troponin.
C)inhibiting Ca⁺⁺ release from the sarcoplasmic reticulum.
D)All of the above answers are correct.

Question 5

Running performances lasting 21 to 60 minutes always involve an energy expenditure equal to VO₂ max.

Question 6

Free radicals can promote muscle fatigue in events lasting longer than 30 min minutes by

A)damaging contractile proteins and limiting the number of cross-bridges bound to actin.
B)blocking action potential transmission across the neuromuscular junction.
C)reducing ATP production.
D)none of the above answers are correct

Question 7

Which of the following has been shown to interfere with cross-bridge "cycling" during exercise?

A)an accumulation of ATP
B)an accumulation of H⁺
C)a decrease in Na⁺
D)a decrease in Pi (inorganic phosphate)

Question 8

Blood buffers would most likely improve performances lasting

A)less than 10 seconds.
B)30 to 180 seconds.
C)3 to 20 minutes.
D)longer than 20 minutes.

Question 9

At three minutes of all-out high-intensity exercise,__________ of the ATP is derived from aerobic sources.

A)10%
B)40%
C)60%
D)90%

Question 10

During exercise,muscle ATP concentrations in skeletal muscles often fall to less than half of resting levels.

Question 11

Having a high VO₂ max would be a primary factor for success in performances lasting

A)less than 10 seconds.
B)30 to 180 seconds.
C)3 to 20 minutes.
D)>4 hours.

Question 12

In events lasting 21 to 60 minutes,the athlete would typically work at _______% VO₂ max.

A)<50
B)<60
C)<70
D)<90

Question 13

Fatigue refers to

A)the sensation of pain associated with repeated muscle contractions.
B)an inability to maintain power output during repeated contractions.
C)the feeling of sleepiness that occurs during repeated muscle contractions.
D)an increased free radical production that occurs during repeated muscle contractions.

Question 14

When the intensity of exercise exceeds 75% of VO₂ max,which of the following fibers are likely brought into play?

A)Type I
B)Type IIa
C)Type IIx
D)Type Ix

Question 15

In aerobic performances lasting 3 to 20 minutes,which of the following factors do not contribute to performance?

A)VO₂ max
B)Maximal cardiac output
C)depletion of muscle glycogen
D)Fiber type

Question 16

A subject,with eyes closed,repeatedly contracts a muscle until fatigue occurs.When the eyes are opened,the muscle's ability to produce force is improved.This experiment is a demonstration of fatigue being linked to which of the following sites?

A)muscle
B)central nervous system
C)mitochondria
D)peripheral nervous system

Question 17

Compared to studying muscle function in vivo,using an isolated single muscle fiber to study muscle fatigue provides which of the following advantages?

A)measurements of ions and metabolites within fiber possible
B)force production of the single fiber can be measured
C)environment identical to in vivo conditions
D)Both A and B are correct

Question 18

One disadvantage of studying muscle fatigue in vivo is that________________.

A)these studies often produce correlative data and it is difficult to identify mechanisms.
B)these studies are not physiological.
C)these studies only allow the study of fatigue during endurance events.
D)None of the above.

Question 19

Running economy becomes an increasingly important determinant of success as the duration of the performance increases.

Question 20

In examining the mechanisms for exercise-induced fatigue,the vast majority of the evidence points to the

A)central nervous system
B)the alpha motor neuron in the spinal cord
C)periphery (i.e. ,peripheral fatigue)
D)Both A and B are correct

Question 21

Poor running economy can have a negative impact on running performance in events lasting 21-60 minutes.