Exercise in operation (7)

I believe the answer is:

running

I believe this is a double definition.

'exercise' is the first definition.
(thesaurus)

'in operation' is the second definition.
(thesaurus)

(Other definitions for running that I've seen before include "on the move" , "No chance if you're out of it" , "In operation" , "Directing" , "Management" .)

I've seen this clue in The Times.

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