isometric exercise vs exercise

isometric exercise and exercise both are nouns.

Word	Noun	Adjective	Verb	Adverb
isometric exercise	Yes	No	No	No
exercise	Yes	No	Yes	No

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

isometric exercise: muscle-building exercises (or a system of musclebuilding exercises) involving muscular contractions against resistance without movement (the muscles contracts but the length of the muscle does not change)
exercise: the activity of exerting your muscles in various ways to keep fit

Other hypernyms of isometric exercise include exercising, physical exercise, physical exertion, workout.

isometric exercise (noun)	exercise (noun)
muscle-building exercises (or a system of musclebuilding exercises) involving muscular contractions against resistance without movement (the muscles contracts but the length of the muscle does not change)	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

isometric exercise (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