Former partner, English, cries, spoiling workout (8)
I believe the answer is:
exercise
'workout' is the definition.
(I know that workout can be written as exercise)
'former partner english cries spoiling' is the wordplay.
'former partner' becomes 'ex' (an ex-partner).
'english' becomes 'E' (abbreviation as in OED).
'spoiling' is an anagram indicator.
'cries' anagrammed gives 'rcise'.
'ex'+'e'+'rcise'='EXERCISE'
(Other definitions for exercise that I've seen before include "Physical activity done for health and fitness" , "keep physically fit" , "Task for pupil" , "worry" , "Keep-fit" .)