Going up without using a track (5)
I believe the answer is:
scent
'track' is the definition.
(both can mean a trace left by someone)
'going up without using a' is the wordplay.
'going up' becomes 'ascent' (ascending means going up).
'without using' is a deletion indicator.
'ascent' with 'a' removed is 'SCENT'.
(Other definitions for scent that I've seen before include "Animal smell" , "Track; aroma" , "Clue" , "Whiff" , "Distinctive smell" .)