Anatomy & Physiology Musculoskeletal #34


Which is the cause of muscle fatigue?


  1. Lack of protein
    • Rationale:

      While many proteins contribute to the muscle’s ability to contract, muscle fatigue is not caused by a lack of protein.

  2. Lack of glucose
    • Rationale:

      While glucose provides important fuel for muscle contraction, a lack of this substance is not the cause of muscle fatigue.

  3. Lack of magnesium sulfate (MgSO4)
    • Rationale:

      While MgSO4 is believed to play a role in muscle relaxation, a lack of this substance is not the cause of muscle fatigue.

  4. Lack of adenosine triphosphate (ATP)
    • Rationale:

      Muscle fatigue is the result of overstimulation of the muscles. It is caused by a lack of ATP within the body.


Muscle fatigue is defined as a decrease in power production in response to contractile activity.


Learning Outcomes

Skeletal muscle contractions generate body heat because much of the body is composed of these muscles. Cells release a substance known as adenosine triphosphate (ATP) to supply energy for muscle contractions. Muscle fatigue occurs when a muscle cannot regenerate ATP.

Test Taking Tip

Consider the role of each choice in muscle movement to answer this question correctly.

Video Rationale