For a very long period of time I have observed the following - it's pretty hard to see meaningful progress using conventional one body part per week routines. I believe the biggest reason for that is that muscle growth (improvement) requires higher frequency if you are not using synthetic hormones. Does this mean that you should train each body part twice a week?
The problem with training each body part twice a week is that you would have to be spending more time in the gym which costs money and time. However since many people "just do it for the fun" I guess the presented reason is not sufficient.
Imagine that you are trying to play too many sports - soccer, running, basketball, swimming...etc. Obviously you can do all those sports at the same time. You can probably even do them every day. However you won't improve significantly. You may be genetically gifted in one area but that's about it. In order for you to become a good basketball player you can't afford to swim like you are trying to beat Michael Phelps records. Not gonna happen.
If we take the same principle and apply it to weightlifting you will see why trying to improve all your body parts at the same time can quite often result in failure because the frequency needed for improvement is simply not there. Let's take a look at a classic one body part per week bodybuilding routine:
Day 1: Chest and Back
Bench press - 3x10-12
Incline - 3x10-12
Flies - 3x10-12
Deadlifts - 3x6-8
Pull-ups - 3x10-12
Rows - 3x10-12
Day 2: Shoulders and Arms
Overhead press - 3x10-12
Lateral raises - 3x10-12
Rear delt raises - 3x10-12
Barbell curls - 3x10-12
Triceps extensions - 3x10-12
Day 3: Legs
Squat - 3x10-12
Leg press - 3x10-12
Hamstring curl - 3x10-12
Calve raises - 3x10-12
Seated calve raises - 3x10-12
This is the most generic routine I was able to create. It's not bad routine by any means. It's obviously hard work. The problem here is that it does not allow you to see meaningful progress in short period of time unless you are just starting working out. This is why I recommend that you start using specialization in your workouts if you have been training for more than a year.
What is specialization training?
Specialization is the process of focusing on one specific task and trying to improve. In our case specialization training means that we are going to focus on specific muscle groups instead of trying to see results everywhere.
How to do it?
The first thing you need to do is decide which body part(s) you are trying to improve. Obviously if you choose back, legs and biceps you are not really doing specialization training since those muscle groups form 85% of your body. A specialization routine requires you to focus on one thing at a time. The choices are legs (quads, calves and hamstrings), arms (triceps, forearms and biceps), chest, shoulders, back...
Don't combine a lot of muscle groups.
Don't combine a lot of muscle groups.
Frequency
The hardest part to determine when it comes to specialization training is - "How often?". There are many factors to consider: age, motivation, training history, money...etc. I think that 3 times per week is a good start. You can later move to 5 days per week.
Choosing the right exercises
In order for any routine to work you have to choose the right exercise for the job. Make sure you focus on basic movements which do not cause pain on your joints. Also avoid doing too many exercises. If you want to add volume (do more) simply perform more sets of the exercises you feel are the best for your current physical condition.
Choosing the right weight
Since you will be training quite don't go too heavy. 60-70% of your 1 RM* is enough. This means that if you can bench press 200lbs a few times you should use about 135-145 lbs for your workouts. It may not sound like a lot but given the frequency and volume it will be.
Putting everything together
Let's say that you want to improve your arms. In order to do that you will have to focus on just that body part while maintaining everything else. This means that your arm muscles will be "murdered" with high volume and frequency while you will do a lot less sets for the rest of your body. Here's a basic arm focused routine:
Day:1 Arms
Bench press with a close grip - 3x10-12
Triceps exercise of choice - 5x10-12
Chin-ups - 3x10-12
Biceps curls - 10-12
Forearm work
Day:2 Legs
Day 3: Arms (same as day1)
Day 4: Rest
Day 5: Arms (same as day1)
Triceps exercise of choice - 5x10-12
Biceps curls - 10-12
Day 6&7 Rest
In order for this routine to work you will have to use moderate weight otherwise you will get hurt.
How long?
I think that 3 months is the magic number. I don't know why but any meaningful progress whether it's weight loss or muscle gain requires at least 3 months. That's why I recommend that you stick to a specialization routine for at least 3 months.
Over training
Overtiring seems to be a big issue. It's hard for me to tell how much your body can handle. I can over train my shoulders really fast while I can work my back 5 times a week with no problem. You have to experiment.
"Good judgement comes from experience. Experience comes from bad judgement." -- Jim Horning
The fastest way to over train is to use too much weight (above 80% of your1 RM*) and to do too many sets. Don't do it.
Don't underestimate your body but stay safe too!
Be realistic
Many people are used to seeing bodybuilding freaks on stage. The problem here is that many of you don't realize what it takes to achieve similar physiques and how many drugs you have to consume in order to get there. That's the main reason for unrealistic expectations. No, by following specialization program your arms will not be 20 inches. If you are interested how natural bodybuilders look just read some of my previous posts.
FAQ:
Q: How long will it take for me to see progress?
A: Like I said - three months is the golden time period.
Q: Should I eat like crazy when doing this routine?
A: No, you should eat enough not to be hungry but not until you feel like you are about to vomit. Simply eat a few times a day and make sure your consume about 150 grams of protein. No need to "bulk". Getting fat on purpose is yet to work for anyone.
Q: Should I focus on another body part after three months?
A: Yes.
Q: Would I see faster progress if I focus on my whole body?
A: If you are a beginner you should. Otherwise you won't have the time and the recovery ability to work your whole body as frequently and as intensely as you need to do as a natural trainee.
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* 1RM = one rep maximum or the heaviest weight you can do for 1 repetition
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