Take up song and dance exercise (5)
I believe the answer is:
adopt
'take up' is the definition.
('adopt' can be a synonym of 'take up')
'song and dance exercise' is the wordplay.
'song and dance' becomes 'ado' (I've seen this before).
'exercise' becomes 'pt'.
'ado'+'pt'='ADOPT'
(Other definitions for adopt that I've seen before include "Choose as one's own" , "Accept as one's own" , "Start to wear" , "Acquire" , "Take responsibility for" .)