A sprinter feels cramps and pain in the thigh muscles after a run. This is due to accumulation of

Accumulation of which one of the following in the muscles of sprinters leads to cramp?

Muscle fatigue is due to accumulation of

Pulse is felt due to the rhythmic contraction and relaxation of the

In the human body, blood flows through a process of double circulation. Which one of the following statements is true in this regard ?

Which of the following is responsible for muscle fatigue?