Exercises help us to get money (5)
I believe the answer is:
pesos
'money' is the definition.
(I've seen this before)
'exercises help us' is the wordplay.
'exercises' becomes 'pe' (Physical Education class).
'help us' becomes 'sos' (distress message Save Our Souls).
'pe'+'sos'='PESOS'
'to get' is the link.
(Other definitions for pesos that I've seen before include "Poses for Mexican coins" , "Mexican dollars" , "Poses for Mexican money" , "Mexican monetary units" .)