Run at full speed over a short distance (6)
I believe the answer is:
sprint
<span class="explanation-format__ClueExplanation">'<span class="explanation-format__original">run at full speed over a short distance</span>' is the definition.<br/ ><span class="explanation-format__explanation">(I've seen this before)</span><br/ ><br/ >This is the entire clue.<br/ ></span>
(Other definitions for sprint that I've seen before include "Short fast run" , "quick run" , "Rush" , "Run at full speed for a short distance" , "Short race at full speed" .)