Exercises before first of several drinks (5-3)
I believe the answer is:
press-ups
'exercises' is the definition.
(press-up is a kind of exercise)
'before first of several drinks' is the wordplay.
'before' becomes 'pre'.
'first of' says to take the initial letters.
'drinks' becomes 'sups' (I've seen this before**).
The first letter of 'several' is 's'.
'pre'+'s'+'sups'='PRESS-UPS'
(Other definitions for press-ups that I've seen before include "Exercises done facing the floor" , "Exercises performed face down" .)