exercise set vs exercising

exercise set and exercising both are nouns.

Word	Noun	Adjective	Verb	Adverb
exercise set	Yes	No	No	No
exercising	Yes	No	No	No

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

exercise set: several exercises intended to be done in series
exercising: the activity of exerting your muscles in various ways to keep fit

Other hypernyms of exercise set include exercise, physical exercise, physical exertion, workout.

exercise set (noun)	exercising (noun)
several exercises intended to be done in series	the activity of exerting your muscles in various ways to keep fit