1 hour of intense exercise (minimal breaks) >>> 3 hours of exercise with a ton of breaks and loitering around.

There's a lot of literature that workouts beyond an hour-hour and a half don't add much benefits and the shorter and more intense they are, the better. (of course this does not apply to athletes)

thats what I do. Wake up 7, gym till 8:30, then work with break for food once every 2 hours for 5 minutes (plus bigger dish at evening) then from 10 to 11 cardio, sleep before 12. I do not exercise over the weekends, let body sleep longer, rest, be lazy. If I manage my time properly, I still easily get 10 hours of work a day! I just noticed how much detracting certain things are: talking 5 times about the same thing over the phone with friend, watching TV "only" for couple minutes, browsing web, reading emails that I know I will come back to again later on, etc. It all adds up substantially. The only spoil other than energy drink with 30g of sugar (my daily rate) I let myself to do is to "waste" time here and there on reading HN :)