PE room demands some energy maybe (3)
I believe the answer is:
gym
'pe' is the definition.
(I've seen this before)
'some energy maybe' is the wordplay.
'some' indicates a hidden word (some parts of the word are used).
'GYM' is hidden within 'energy maybe'.
'room demands' acts as a link.
I am not very happy about this link. Some or all of it may be part of another bit of the clue.
Can you help me to learn more?
(Other definitions for gym that I've seen before include "Place to work out" , "PE" , "Place of exercise" , "Lesson" , "Physical training facility, in short" .)