Sports coach churned up terrain (7)
I believe the answer is:
trainer
'sports coach' is the definition.
(I've seen this before)
'churned up terrain' is the wordplay.
'churned up' is an anagram indicator.
'terrain' is an anagram of 'TRAINER'.
(Other definitions for trainer that I've seen before include "Soft shoe; simulator" , "Sports shoe" , "one that helps runner perform" , "Sports coach" , "Soft shoe, small aircraft" .)