athletic competition vs athletics

athletic competition and athletics both are nouns.

Word	Noun	Adjective	Verb	Adverb
athletic competition	Yes	No	No	No
athletics	Yes	No	No	No

As nouns, athletic competition and athletics are synonyms defined as:

Other synonyms of athletic competition include athletic contest.

athletic competition (noun)	athletics (noun)
a contest between athletes	an active diversion requiring physical exertion and competition
	participation in sports events as an extracurricular activity
	a contest between athletes