Inward exercise gets out of shape (6)
I believe the answer is:
warped
'out of shape' is the definition.
(I've seen this before)
'inward exercise gets' is the wordplay.
'inward' becomes 'ward' (I am not sure about this - if you are sure you should believe this answer much more).
'exercise' becomes 'pe' (Physical Education).
'gets' means one lot of letters goes inside another.
'ward' going around 'pe' is 'WARPED'.
Can you help me to learn more?
(Other definitions for warped that I've seen before include "Twisted like wood in sun" , "Bent out of shape by damp or heat" , "Twisted out of shape" , "Twisted like wood from heat" , "Perverse" .)