There's no other way to say this, so let's get it out of the way: Plateaus aren't fun. Getting stuck in a training rut where you make no progress can be frustrating and may even lead you to thinking you should find something else to do. Well, you should.
I don't mean stop training, though. I mean you need to find something else to do in the gym to help you get back on the road to achieving your goals. The classic individual body-part routine, aka the bro-split, is a great place to start, but eventually, it's time for a change to your workout schedule, and this may be that time for you. Take a look at these three splits and pick one that will help get you moving onward and upward again.
If you're trying to get stronger, this may be your best choice. It's the routine that many iron rookies start with when they begin their training, but that doesn't mean it can't be of help to weight-room veterans. Sometimes going back to basics is best. Doing this routine now, after training yourself into a plateau, would be a good option because you have a more advanced knowledge of your body and how to perform the lifts. Following a split like this can bring back that sense of excitement you had when you began.
To maximize recovery, train one day on/one day off. Train abs at every other workout.
If you're trying to add size and have been stuck on a plateau, do what some of the greats of the Golden Era did. Pair up opposing muscle groups like chest and back or biceps and triceps, and do supersets—one exercise for the push muscle followed by one for its opposing pull muscle. The idea is to pump as much blood as possible into the overall area and both muscles get the benefit and respond.
You train four days a week on this split: two days on/one day off/two days on/two days off.
If splits like this worked for the champions of the past, this one will work for you.
Day 1: Chest & Back
Perform the exercises in order with no rest between exercises and 1 min. of rest between rounds.
You may have seen several articles and videos about upper-body/lower-body splits, and it's for good reason—they work. While you're still performing a lot of overall training volume here, you may not be working each individual area as much. Doing 3-4 workouts a week like this may be the ticket for you to get back on the gains train. Pay attention to the way this split is set up because it isn't organized around a week of training. Instead, it's a simple two days on/one day off rotation.