high bar vs exerciser

high bar and exerciser both are nouns.

Word	Noun	Adjective	Verb	Adverb
high bar	Yes	No	No	No
exerciser	Yes	No	No	No

As nouns, exerciser is a hypernym of high bar; that is, exerciser is a word with a broader meaning than high bar:

high bar: gymnastic apparatus consisting of a bar supported in a horizontal position by uprights at both ends
exerciser: sports equipment used in gymnastic exercises

Other hypernyms of high bar include gymnastic apparatus.

high bar (noun)	exerciser (noun)
gymnastic apparatus consisting of a bar supported in a horizontal position by uprights at both ends	sports equipment used in gymnastic exercises