Exercise too much without shower in public (5)
I believe the answer is:
overt
'in public' is the definition.
(I've seen this before)
'exercise too much without shower' is the wordplay.
'exercise too much' becomes 'overtrain'.
'without' indicates named letters should be taken away.
'shower' becomes 'rain' (rainfall).
'overtrain' with 'rain' taken away is 'OVERT'.
(Other definitions for overt that I've seen before include "not disguised" , "Open, not secret or hidden" , "____ is able to be seen" , "Open and observable" , "Open,up front" .)