tummy crunch vs exercise

tummy crunch and exercise both are nouns.

Word	Noun	Adjective	Verb	Adverb
tummy crunch	Yes	No	No	No
exercise	Yes	No	Yes	No

As nouns, exercise is a hypernym of tummy crunch; that is, exercise is a word with a broader meaning than tummy crunch:

Other hypernyms of tummy crunch include exercising, physical exercise, physical exertion, workout.

tummy crunch (noun)	exercise (noun)
an exercise designed to strengthen the abdominal muscles	the activity of exerting your muscles in various ways to keep fit
	a task performed or problem solved in order to develop skill or understanding
	systematic training by multiple repetitions
	the act of using
	an action, often used negatively and without consequences
	(usually plural) a ceremony that involves processions and speeches

tummy crunch (verb)	exercise (verb)
	do physical exercise
	give a workout to
	learn by repetition
	put to use
	carry out or practice; as of jobs and professions