Space to stretch, sleep regularly, and prepare (7)
I believe the answer is:
Here is my best explanation:
'space to stretch' is the definition.
(I've seen this before)
'sleep regularly and prepare' is the wordplay.
'regularly' indicates alternate letters (regularly take one letter, leave next etc.).
'and' is a charade indicator (letters next to each other).
'prepare' becomes 'groom' (synonyms).
The alternating letters of 'sleep' are 'le'.