Worker and speaker taking exercise (8)
I believe the answer is:
operator
'worker' is the definition.
(I've seen this before)
'speaker taking exercise' is the wordplay.
'speaker' becomes 'orator' (orator is a kind of speaker).
'taking' indicates putting letters inside.
'exercise' becomes 'pe' (Physical Education).
'orator' placed around 'pe' is 'OPERATOR'.
'and' acts as a link.
(Other definitions for operator that I've seen before include "Wheeler-dealer - telephonist" , "Switchboard employee" , "User of machinery" , "Mathematical symbol" , "User of machine etc" .)