Endurance, so to speak (4)
I believe the answer is:
legs
<span class="explanation-format__ClueExplanation">'<span class="explanation-format__original">endurance so to speak</span>' is the definition.<br/ ><span class="explanation-format__explanation">(I've seen this in another clue)</span><br/ ><br/ >This is the entire clue.<br/ ></span>
(Other definitions for legs that I've seen before include "associated with 11 in game" , "Lower limbs" , "Members" , "Stages of a journey" , "Sections of a journey or course" .)