Unless you're terribly out of shape to start, there's no reason that you shouldn't be able to complete this workout in well under an hour. (weightrainer.net)
Have you ever looked in the mirror after completing a workout program only to experience sadness and frustration because you didn't see the muscular size and definition you were looking for? (bodyweightoverload.com)
Give it a try in your next workout to test the concept then try a couple of complete workouts with it. (muscle-fitness-training.com)