Exercises around meadow or fold (5)
I believe the answer is:
pleat
'fold' is the definition.
(I know that pleat is a type of fold)
'exercises around meadow' is the wordplay.
'exercises' becomes 'PT' (Physical Training).
'around' means one lot of letters goes inside another.
'meadow' becomes 'lea' (a lea is a grassy area).
'pt' enclosing 'lea' is 'PLEAT'.
'or' is the link.
(Other definitions for pleat that I've seen before include "Fold in clothing" , "Flat fold of cloth" , "Leapt (anag)" , "Crease" , "Fold pressed or stitched into cloth" .)