hurdling vs hurdle race

hurdling and hurdle race both are nouns.

Word	Noun	Adjective	Verb	Adverb
hurdling	Yes	No	No	No
hurdle race	Yes	No	No	No

As nouns, hurdling and hurdle race are synonyms defined as:

hurdling and hurdle race: a footrace in which contestants must negotiate a series of hurdles

Other synonyms of hurdling include hurdles.

hurdling (noun)	hurdle race (noun)
a footrace in which contestants must negotiate a series of hurdles	a footrace in which contestants must negotiate a series of hurdles