Question

Amber goes to workout one day and is so into her music that she continues her workout for 1 hour without taking a break, leading to extreme muscle fatigue and she can not continue. The next day Amber goes to workout and takes two 15 minute breaks to talk to her friends which allows her to complete a full 2 hour workout.

1. Why was Amber able to work out for a longer amount of time when she took the two 15 min breaks?

A. During relaxation ATP build up is able to decrease, delaying muscle fatigue

B. During relaxation ATP and acetylcholine can increase, delaying muscle fatigue

C. During relaxation build up of ADP can decrease, delaying muscle fatigue

D. During relaxation build up of Pi and lactic acid can decrease, delaying muscle fatigue

E. More than one answer is correct

2. While Amber is doing her workout she decides to try lifting heavier weights. She usually uses 8lb weights but wants to try 12lb weights. When she tries to lift up the 12lb weight she is unable to, why?

A. The force created was more than the weight that she was trying to pick up

B. The force created was less than the weight she was trying to pick up

C. The force created was the same as the weight she was trying to pick up

D. No force was created

E. More than one answer is correct

3. The next day Amber got home from work and was extremely hungry so she ordered 1 large pizza and finished it herself. After eating the pizza she was supposed to walk her dog and go workout but she felt too tired and was extremely lazy so she did not do anything. Why did this happen?

A. The sympathetic nervous system took over and caused her heart rate to decrease

B. The parasympathetic system took over which caused her heart rate to stay the same

C. The sympathetic nervous system took over which caused her heart rate to increase

D. The parasympathetic nervous system took over which caused her heart rate to increase

E. The parasympathetic nervous system took over and caused her heart rate to decrease

Answer 1

1. (E) More than one answer is correct.

Both options (B) and (D) are correct. Accumulation of metabolic waste products like lactic acid and depletion of acetyl choline are causes of fatigue. Giving rest is a factor favouring fatigue recovery and hence relaxation will increase ATP and acetyl choline production and removes the accumulated waste products from muscle.

2. (E) More than one answer is correct.

Both options (B) and (C) are correct. When Amber tries to lift up 12 lb weight, she has to produce a force more than the weight she is trying to lift up and hence we can conclude she is unable to do so because the force created by her is either equal to or less than the weight she is trying to lift.

3. (E) The parasympathetic nervous system took over and caused her heart rate to decrease.

Since parasympathetic system got stimulated, the decrease in heart beat has resulted in decreased cardiac output and hence decreased nutrient and oxygen supply to tissues and organs including brain resulting in tiredness and inability to do work.