Question 1

A high H+ concentration can contribute to fatigue by

Accepted Answer

A)  reducing the force per cross-bridge. 
B)  interfering with Ca++ binding to troponin. 
C)  inhibiting Ca++ from the sarcoplasmic reticulum. 
D)  all of the above. D

Question 2

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

Accepted Answer

A)  less than 10 seconds. 
B)  30 to 180 seconds. 
C)  3 to 20 minutes. 
D)  all of the above. B

Question 3

Free radicals may promote muscle fatigue by

Accepted Answer

A)  damaging contractile proteins and limiting the number of cross-bridges. 
B)  blocking action potential transmission across the neuromuscular junction. 
C)  reducing ATP production. 
D)  none of the above; free radicals do not promote muscle fatigue. A

Question 4

In short-term performances (10-180 seconds) which of the following factors is the primary cause of fatigue?

Accepted Answer

A)  muscle glycogen depletion 
B)  depressed plasma FFA 
C)  hypoglycemia 
D)  H+ accumulation

Question 5

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

Accepted Answer

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

Question 6

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

Accepted Answer

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

Question 7

Carbohydrate supplementation during exercise is most important in performances lasting

Accepted Answer

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

Question 8

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

Accepted Answer

A) True 
 B)False

Question 9

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

Accepted Answer

A) True 
 B)False

Question 10

Reaction time and skill would be most important for

Accepted Answer

A)  a marathon runner. 
B)  a cross-country runner. 
C)  a sprinter competing in the 100-m dash. 
D)  all of the above.

Question 11

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

Accepted Answer

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

Question 12

Blood buffers would most likely improve performances lasting

Accepted Answer

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

Question 13

What is the primary energy source in ultra short-term performances (less than 10 seconds)?

Accepted Answer

A)  muscle glycogen 
B)  phosphocreatine 
C)  blood glucose 
D)  plasma FFA

Question 14

In aerobic performances lasting 3 to 20 minutes, which of the following factors limits performance?

Accepted Answer

A)  VO2 max 
B)  creatine phosphate depletion 
C)  availability of carbohydrate supplementation 
D)  availability of plasma FFA

Question 15

Fatigue refers to

Accepted Answer

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 16

A subject, with eyes closed, repeatedly contracts a muscle until fatigue occurs. When the eyes are opened, tension is restored. This experiment is a demonstration of fatigue being related to which of the following sites?

Accepted Answer

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

Question 17

Running performances lasting 21 to 60 minutes are conducted at an energy expenditure equal to VO2 max.

Accepted Answer

A) True 
 B)False

Question 18

Fatigue can be viewed as an imbalance between ATP requirements and ATP production.

Accepted Answer

A) True 
 B)False

Exam 19: Factors Affecting Performance

A high H⁺ concentration can contribute to fatigue by

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

Free radicals may promote muscle fatigue by

In short-term performances (10-180 seconds) which of the following factors is the primary cause of fatigue?

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

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

Carbohydrate supplementation during exercise is most important in performances lasting

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

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

Reaction time and skill would be most important for

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

Blood buffers would most likely improve performances lasting

What is the primary energy source in ultra short-term performances (less than 10 seconds) ?

In aerobic performances lasting 3 to 20 minutes, which of the following factors limits performance?

Fatigue refers to

A subject, with eyes closed, repeatedly contracts a muscle until fatigue occurs. When the eyes are opened, tension is restored. This experiment is a demonstration of fatigue being related to which of the following sites?

Running performances lasting 21 to 60 minutes are conducted at an energy expenditure equal to VO₂ max.

Fatigue can be viewed as an imbalance between ATP requirements and ATP production.