Shift time for sport (8)
I believe the answer is:
dressage
'for sport' is the definition.
(dressage is a kind of sport)
'shift time' is the wordplay.
'shift' becomes 'dress' (shift can mean a dress).
'time' becomes 'age' (an age is a period of time).
'dress'+'age'='DRESSAGE'
(Other definitions for dressage that I've seen before include "The training of a horse in manoeuvres" , "Part of equestrian event" , "Equestrian manoeuvres" , "equestrian routine" , "Equestrian performance" .)