How one might make the bar, panting (3,2,6)
I believe the answer is:
out of breath
'panting' is the definition.
(thesaurus)
'how one might make the bar' is the wordplay.
'how one' becomes 'outof' (I can't justify this - if you can you should believe this answer much more).
'might make' is an anagram indicator (the letters might make if rearranged).
'the'+'bar'='thebar'
'thebar' with letters rearranged gives 'breath'.
'outof'+'breath'='OUT-OF-BREATH'
(Other definitions for out of breath that I've seen before include "Gasping" , "pants?" .)