Beer bottles finished off, German exercises (7)
I believe the answer is:
pilates
'german exercises' is the definition.
'pilates' can be an answer for 'exercises' (I've seen this before). I'm not sure about the 'german' bit.
'beer bottles finished off' is the wordplay.
'beer' becomes 'pils' (Pilsner beer).
'bottles' means one lot of letters goes inside another (bottle can mean to contain).
'finished off' becomes 'ate' (finished eating).
'pils' going around 'ate' is 'PILATES'.
Can you help me to learn more?
(Other definitions for pilates that I've seen before include "Set of exercises used in holistic medicine" , "Holistic system of physical exercises" , "Pleats I arrange into a form of exercise" , "Modern exercise" , "discipline?" .)