It depends on what level you are at....
If you happen to be a guy whose arms are barely 14 inches..... you had better get you ass to the gym at least three times a week.... the good old MON, WED & FRI thing.
If you have pipes that are 16 and up then I consider you an intermediate and then you would show up at the gym four times a week..... working each body part only twice per week..... this is an example of what I mean....
MON & THUR: Legs, Back, Bicpes and Forearms
TUES & FRI: Calves, Chest, Shoulders and Triceps
Abs can be worked anytime and shoud be to strengthen you midsection and they can be couple with hyperextensions as well.
Maxmuscle66