Worked out tons, then showered (7)
I believe the answer is:
trained
'worked out' is the definition.
(training is a kind of working out)
'tons then showered' is the wordplay.
'tons' becomes 't'.
'then' means one lot of letters go next to another.
'showered' becomes 'rained' (showers of rain).
't'+'rained'='TRAINED'
(Other definitions for trained that I've seen before include "Taught (to do a job)" , "Taught, educated" , "Instructed - took aim" , "I daren't (anag)" , "Taught; exercised" .)