Forced, prisoners exercised (11)

I believe the answer is:

constrained

'forced' is the definition.
('constrained' can be a synonym of 'forced')

'prisoners exercised' is the wordplay.
'prisoners' becomes 'cons'.
'exercised' becomes 'trained' (training is a kind of exercising).
'cons'+'trained'='CONSTRAINED'

(Other definitions for constrained that I've seen before include "Awkward" , "Embarrassed" , "Appearing forced" , "with shackles on" , "Reticent" .)

I've seen this clue in The Times.

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