Show recent changes in gym (8)
I believe the answer is:
pretence
'show' is the definition.
(a pretence can mean something done for show)
'recent changes in gym' is the wordplay.
'changes' is an anagram indicator.
'in' indicates putting letters inside.
'gym' becomes 'pe' (short for Physical Education).
'recent' anagrammed gives 'retenc'.
'retenc' placed into 'pe' is 'PRETENCE'.
(Other definitions for pretence that I've seen before include "Ten creep (anag.)" , "False show hiding reality" , "Act of imagination" , "Sham" , "Deceit, dissimulation" .)