Eli5: Why is it more comfortable to walk than it is to stand still?

Question

Eli5: Why is it more comfortable to walk than it is to stand still?

In: Biology

Answer 1

Your limbs all have two sets of muscles: for flexing and unflexing. When you stay in one position, both muscles in each set are working at once to keep you stationary. When you move around, they take turns and get less tired.