Showering after end of difficult exercise (8)
I believe the answer is:
training
'exercise' is the definition.
(thesaurus)
'showering after end of difficult' is the wordplay.
'showering' becomes 'raining' (I've seen this before).
'after' is a charade indicator (letters next to each other).
'end of' indicates one should take the final letters.
The last letter of 'difficult' is 't'.
'raining' after 't' is 'TRAINING'.
(Other definitions for training that I've seen before include "Aiming" , "Process of education" , "Working out" , "The holding of an office" , "Coaching" .)