But it must be understood, that unless designed otherwise, i.e. unless the Units of Analysis are chosen from all people, most studies are generalizable only for a much narrower population of the people w/in a nation, region, city, etc.
exercising - the activity of exerting your muscles in various ways to keep fit; the doctor recommended regular exercise; he did some exercising; the physical exertion required by his work kept him fit. exercise, physical exercise, physical exertion, workout.
exercise noun (PRACTICE) C2 [ C ] an action or actions intended to improve something or make something happen: Ships from eight navies will be taking part in an exercise in the Pacific to improve their efficiency in combat. It would be a useful exercise for you to say the speech aloud several times.