exercising vs physical exercise

exercising and physical exercise both are nouns.

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

As nouns, exercising and physical exercise are synonyms defined as:

exercising and physical exercise: the activity of exerting your muscles in various ways to keep fit

Other synonyms of exercising include exercise, physical exertion, workout.

exercising (noun)	physical exercise (noun)
the activity of exerting your muscles in various ways to keep fit	the activity of exerting your muscles in various ways to keep fit