Loathes running heats! (5)
I believe the answer is:
hates
'loathes' is the definition.
(I've seen this in another clue)
'running heats' is the wordplay.
'running' indicates an anagram.
'heats' anagrammed gives 'HATES'.
(Other definitions for hates that I've seen before include "Detests" , "can't stand" , "Despises" , "Abhors" , "Dislikes intensely" .)