While I cannot compete with the wisdom and experience of Berin, I want to add my point of view on StrongLift 5x5 and similar programs.
I am in rehab for having pushed too hard and injured my shoulders. This has given me the opportunity to a lot of personal research. I know now what I am going to do when my rehab is over, and it has little to do with barbells.
You want to gain muscle. So do I. I am going to explain why I think it is a bad idea for someone in my situation (and perhaps in yours too) to begin the way leading to muscle gain by weightlifting compound exercises. It doesn't mean that you should never do weightlifting, but rather that (I think) you should do other kind of things first.
People that have been all their lifes doing some kind of sports or physically demanding jobs, don't grasp what being weak feels like. For them, an empty 20 kg olympic barbell is a good starting point. Not for me. Here are some thoughts:
Randomly reading in different forums, I have learnt with horror that it is not uncommon for people to get herniated disks from doing deadlifts without proper form. Paradoxically, the same people are happy that the same exercise, performed with lighter weights and proper form, alleviates their pain months after the injury (hey, there is even one of such testimonies in the Stronglifts report itself!). Believe me, you don't want a herniated or ruptured disk that is going to stay with you for the rest of your life.
The lesson is: unless your form is perfect, it is very easy to do a lot of damage to your spine with deadlifts. And, how easy is to have bad form Deadlifting? Well, Bruce Lee himself got a herniated disk by improperly doing Good-mornings, a quite similar exercise to Deadlifts, at least regarding the lower back. Are you telling me that Bruce Lee had poor control of his body?
Failing to maintain proper form is extremely easy if your are weak. Specially with compound exercises because antagonist muscles must counteract and balance one another. You may struggle to have perfect form while deadlifting, but if your abdominal muscles are weak and don't stand the tension in the middle of the lift, your lower back will curve and thus be very vulnerable.
I am not saying that one should avoid Deadlifts forever, but it may be a good idea to invest some time first, strengthening your core muscles with safer exercises (safer because it is much easier to maintain proper form, and because they don't use external weights) There are many of them: Bridges or Bird Dogs or Supermans for the spinal erectors; Plank or Leg Raises or Sit-ups for your abdominal muscles; Side Planks for your obliques...
One easy way to integrate those exercises in a single one to strengthen your core and abs, is the Rotisserie invented by Scooby.
I short words, I think that, if you cannot stand a plank position for a couple of minutes or do a bunch of situps without wanting to puke, it is probably suicidal to start doing deadlifts.
The same goes for Bent-Over Rows and Back Squats with barbells. Great exercises, yes, but only after you have a minimum of strength and are properly trained to perform them with strictly proper form, otherwise they may be a quick way to injure your lower back. Building a minimum level of core strength by safer means before attempting these lifts is not a bad idea.
2. Bench Press and Overhead Press
During both the bench and the overhead press, it is very important that the shoulder blades and the shoulders in general are stable in their correct position during the lift. A collection of different muscles is responsible for that. The movement of the scapulas is complex and depends upon the well balanced action of that muscles. Again, if that muscles are weak, it is very likely that you will injure your shoulders under a 20 kg barbell. That is probably why Berin recommends you to bench press from the floor, not on a bench. Because the floor gives a better support for your back and restricts the motion to a range that is safer for your shoulders.
But, again, there are safer exercises to strengthen the muscles around your shoulder girdles and upper body in general, in a more natural and balanced way, involving more muscles at the same time. The Pushups. During Pushups, your pectorals and front deltoids are actively working, but the important thing is that the muscles around your scapulas are receiving an isometric workout, helping them become progressively stronger. You can start by doing very easy variations like the Wall Push-Ups, then you may progress to Incline Pushups, after that you have the Kneeling Pushups.
These exercises involve the same muscles as the Bench Press and the Overhead Press and some more, but are easier and safer and they will prepare your body for heavy weights. Additionally, they involve more core stabilizer work, adding safety to your future workouts. Again, I think that, if you cannot perform these exercises, then picking up a 20kg barbell is asking for injuries.
There are more things I don't like in SL5x5. I started doing the Shoulder Dislocations Mehdi recommends (if you don't know what exercise Shoulder Dislocations is, then the better for you). This is a passive stretch exercise that would give you more flexibility around your shoulders. Again, this is good for people that have at least some level of muscular strength. But I did them for a while and noticed with horror how my shoulders became loose and started doing craking noises. Passive stretches might be a good way to improve your ROM when you have strong muscles attached to that joints. If that is not the case, the only thing you get is loose joints, prone to injury. Mehdi constantly does a lot of assertions like the benefits of the shoulder dislocations and other things with no solid background, and you can easily notice that by reading any older version of the StrongLifts report, where you see how he has evolved. For instance, until recently, he stated that the weightlifting belt was useless and only gave a false sensation of safety. He then corrected that in the following version of the report. So, if you still insist in doing a 5x5 program, read Rippetoe's book, at least it has a very good description of the proper form of the lifts.
In summary, if your body is weak and you are prone to bad form, weightlifting and 5x5 programs might not be the best choice to start from (although you may turn to them in the future). Progressive calisthenics exercises are my bet.
You can find a very easy to follow, free progressive calisthenics program in youtube. Here are the links (the guys call themselves calisthenicskingz, I think they have another website where they sell the gloves or something):
- Beginner Calisthenics Program by calisthenicskingz
- Intermediate Calisthenics Program by calisthenicskingz
There is an advanced level too.
But I am going to follow an even more progressive and better structured program, as laid in the book Convict Conditioning. I gave more information about the book in this answer
Another option, if you love weights, are the workouts in Scooby's webpage. He has them structured in several levels, and does emphasize safety a lot. He has a lot of videos with very detailed explanations about all aspects of weightlifting and the proper form of the exercises, and all is free. If you follow his programs, you will nevertheless start by doing pushups, but the following levels is done with dumbbells and barbells, he is a weightlifter.