The upper body/lower body split

The upper body/lower body split is perhaps the simplest split, a good one for beginners to try. You don’t have much to remember: It’s pretty obvious which exercises work the muscles above the belt and which work your muscles down south. When you work your upper body one day and your lower body the next, each zone of your body gets more of a complete rest than for any other way you do your split.
People who do the upper/lower split generally train their abdominals with their lower body, but this isn’t a hard-and-fast rule. Don’t make the mistake of working your abs every workout. Remember, the abs are like any other muscle group: They need time to recover. Two or three abdominal workouts a week will suffice.