Subjected to formal exercise - bored (7)
I believe the answer is:
drilled
'bored' is the definition.
(I've seen this before)
'subjected to formal exercise' is the wordplay.
I cannot really understand how this works, but
'exercise' could be 'drill' (synonyms) and 'drill' is located in the answer.
The remaining letters 'ed' is a valid word which might be clued in a way I don't understand.
This explanation may well be incorrect...
Can you help me to learn more?
(Other definitions for drilled that I've seen before include "soldiers may be treated thus" , "given military instruction" , "Bored a hole or trained by repetition" , "Made a hole with a pointed tool" .)