Technically I usually do it twice within seven days. Since I work at home and have no reason to follow a real week and I don't have any specific appointments or distractions.
1. back/bi's
2. legs
3. cardio only
4. chest/tri/shoulders
5. cardio only
6. rest
then I start all over, I've only been following my I'm a bum and have nothing else to do with most of my day schedule since november and I'll probably mix it up again soon