Yes. The book on it is Body by Science by Dr. Doug McGuff. Hours and hours are not necessary and might even be counterproductive.
I’m going to disagree with the book. I trained for the Olympic decathlon for a decade and still workout 1 1/2 to 2 hours daily. Granted every person is different but just about all studies I’ve read say it’s vigorous daily exercise which increases life expectancy and keeps you healthiest.