hurdles vs hurdle race

hurdles and hurdle race both are nouns.

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

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

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

Other synonyms of hurdles include hurdling.

hurdles (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