If you're a mixed-martial artist, there are 3 pitfalls to following a bodybuilding routine in they gym:

1) The routine will require high volume and thus take time away from martial arts training.

2) The routine will leave your muscles tired and sore, which will take away from martial arts training.

3) The routine promotes muscular hypertrophy, which means that if you follow it properly, you'll have to move to a higher weight class.

Now for most athletes, if you've got to learn wrestling, boxing, muay thai, grappling, and deal with life on top of all of that, a 4-5 day strength training routine is not going to enhance your performance. Add endurance training on top of that and you're probably setting yourself up for overtraining and potential injury.

Even if you can get it in, and it doesn't leave you too sore, you still don't want to add too much muscle. Instead, your goal is for relative strength and power, which means that you want to stay the same weight, but get more and more powerful.

Since your goals are different, your strength training routine needs to be different to address those goals.

That's where you want to begin to think about training movement patterns first and muscles after.

Six basic movement patterns exist:

1) Squat

2) Lunge

3) Bend (aka deadlift)

4) Twist

5) Push

6) Pull

If you integrate these movements into your program, you'll be working every muscle in your body to some degree.

Additionally, when you perform these movement patterns, you may notice deficiencies or strength imbalances. One example is during a lunge - if your forward knee caves in, this means that your glutes (medius and maximus) are either not firing when they should or they're relatively weak. Either way, you know that you've got to do some isolation work to bring up the lagging muscle.

Isolation exercises are not categorized within the movement patterns listed above, but there are some that mixed-martial artists need to be doing, such as isometrics (planks, hangs, etc) and single-joint exercises (external shoulder rotations, bicep curls, etc), in addition to any corrective exercises.

So instead, focus on training movement patterns first, then isolate later.

Now, since you're on the movement pattern paradigm, the biggest benefit for the mixed-martial artist is that you want to train 2-3 times per week to get the most benefit. Since you'll be hitting every major muscle group each time you workout, training more than 3 times a week will interfere with your recovery and leave you too sore and tired to be effective in your MMA training. A sample 2-day split would be:

Day 1: Forward lunges, bench press, chin-ups, skull crushers, and prone bridges.

Day 2: Deadlifts, arnold press, 1-arm rows, bicep curls, and woodchops.

Here you'll be hitting all movement patterns and all major muscle groups. You'll still be making strength gains by following effective rep, set, and rest schemes, you won't be left too sore, and you'll be fresh and ready to absorb effective MMA techniques.

Remember, you're a mixed-martial artist, not a bodybuilder posing in a speedo, so train with one goal in mind - improving your performance in the cage.