There's usually a lot of confusion about which workout routine you should follow when trying to build muscle. There are several options that you can choose from, and just about all of them will work fine if you’re diligent about following the plan and following a strict diet.

Basically, if you’ve passed the beginner’s stage, and your primary objective is to build muscle or improve the way your body looks in virtually any capacity, these workout programs are just for you.

Note: The first 3 workout plans are connected, as suitable for beginners, intermediates, and advanced users, respectively. You can start with your level, and work your way up from there.

3-Day Full Body Routine

This is a 3-days-a-week workout routine. Each workout day is followed by a rest day, and the 3rd workout day is followed by a couple of rest days, since most people will take the weekend off entirely.

This workout is used mostly by beginners, and for many good reasons:

It allows you to get familiar with the exercises by repeating them many times throughout the week.
Since most of the beginners who lift, don’t possess the same strength levels as more advanced lifters, it's good to trigger the muscle more often because the amount of weight lifted is significantly lighter and you won’t need as much time to recover and repair before their next workout.
As a beginner, your body will experience greater gains by training less, rather than training more. Take advantage of this time in your training as you’ll experience the ‘beginner gains' that you may never experience again. You have to allow your body to adapt to exercises, and recover, in order to grow. 3 days is a good start for beginners and it’ll allow you to eventually progress to more volume and more frequency if desired.

4 Day Split

This is actually the next step from the 3-day full-body workouts.

This routine is typically suitable for intermediate trainees.

There are many versions of this, that are being practiced around, but the most common one to follow is performing upper body on the first day, then lower body on the next day, then a rest day, then a repeat (upper body/lower body).

Just like in the 3-day workout plan, you have the choice to take two days off for the weekend or to continue after only 1 day of rest. The problem with only taking one day off instead of the two day weekend is that it throws you off schedule for your next week (if that is important to you).

The reason why this routine is categorized as intermediate is because now that you have been training longer and you have become stronger in your lifts, you’ll need more rest to allow your body to properly heal between the body parts you've trained in your workouts. You’ll back off the frequency you train each muscle but you’ll increase your training by one day.

Once you’ve completed about 3-6 months of the 3-day routine, you can move up to this workout plan, in order to see more muscle gains.

5-Day Split

The 5-day split is one of the most advanced routines recommend for anyone.

Though there are routines that could make you train 7 days a week or even twice per day for a total of 14 workouts per week, eventually the line has to be drawn, and it’s generally at 5 days per week for, 99% of natural trainers.

After training previous splits for multiple years and developing your maximal strength and growth, you might need to start training using a 5-day split routine, focusing on only 1-2 muscle groups per workout.

When you train for more than a couple of years or so, the strength gains you experienced in the beginning don’t happen at the same rate it used to be, due to an adaptation in your central nervous system. Eventually, you’ll reach a point where it’ll be very tough to add more weight to your lifts or even grow additional muscle.

At this point, it's better to increase the volume trained on the muscle on the day you work it and allow a longer cycle for it to repair fully and to stimulate growth.

Apart from these 3, there are many other muscle building workout plans for any stage.

Jim Stoppani's 12-week Shortcut to Size.

Shortcut to Size is a three-phase training program, designed by Jim Stoppani, PhD., based on “microcycles” that help you progressively build muscle and strength each and every week. The plan includes four workouts per week, and it’s more suitable for novices as well as intermediates.

Steve Cook’s Big Man On Campus.

With a 4-day body-part split, plus 3 active recovery days, the workout schedule allows you to build some serious muscle, while budgeting your time to successfully balance fitness, with other aspects of your life.

The Ultimate Total-Body Workout Routine to build MAXIMUM muscles.

Total-body workouts may sound like they take a lot of time. But when you boil down the exercises needed to cover every area, there are only three of your concern—pushes, pulls, and squats. This is the ultimate in minimalism, and works superbly for beginners or people who are short on time.

If you’ve trained on and off over many years but never actually commit to any program, then you should consider yourself to be an intermediate, but you can even start as a beginner, to condition your body for the higher volume training to come later on. It's your choice.

Decide what your level of training is, and then choose a routine that suits your individual requirements. Remember to be patient and focus on one thing at a time, and you’ll start to progress through each routine and see some very impressive gains.