Fitness club (3)
I believe the answer is:
gym
<span class="explanation-format__ClueExplanation">'<span class="explanation-format__original">fitness club</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 gym that I've seen before include "In brief, exercise room" , "PE" , "Exercise (hall)" , "Briefly, a keep-fit place" , "Physical education" .)