physical exercise vs workout

physical exercise and workout both are nouns.

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

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

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

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

physical exercise (noun)	workout (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