Showering after time working out (8)
I believe the answer is:
training
'working out' is the definition.
(training is a kind of working out)
'showering after time' is the wordplay.
'showering' becomes 'raining' (as in showers of rain).
'after' is a charade indicator (letters next to each other).
'time' becomes 't' (abbreviation).
'raining' put after 't' is 'TRAINING'.
(Other definitions for training that I've seen before include "Vocational education" , "Process of education" , "Learning a skill" , "The holding of an office" , "Preparing for athletic performance" .)