Riding a horse in short bursts? (7)
I believe the answer is:
hacking
I believe this is a double definition.
'riding a horse' is the first definition.
(to hack is to ride a horse for fun)
'in short bursts?' is the second definition.
(as in a hacking cough)
(Other definitions for hacking that I've seen before include "Riding, coughing" , "way of accessing computer system" , "Gaining unauthorised access to computer data" , "Cutting" , "Striking" .)