Cease sports training over problems at outset (4)
I believe the answer is:
stop
'cease' is the definition.
('stop' can be a synonym of 'cease')
'sports training over problems at outset' is the wordplay.
'at outset' says to take the initial letters.
The first letters of 'sports training over problems' is 'STOP'.
(Other definitions for stop that I've seen before include "Cease, halt" , "Red light signal" , "Arrest" , "Cease; organ voice" , "Hold on" .)