I've started lifting only recently, but I was too stupid to take the time to fix some pretty bad weaknesses and imbalances that are holding me back. I want to take some time and focus on my core and back, both of which are pathetically weak even compared to the rest of my body, which is also pretty damn weak. Being a beginner, I have no idea about how to approach this problem.
Ive read Alwyn Cosgrove's "Why You Aren't Getting Bigger- And How to Fix It", and I'm getting some idea of what I should be doing, but I want the opinion someone more experienced to make sure I'm on the right track.
Straight out of the article, for core strength...
Side plank -60 sec each side
Weighted Overhead Lunge -60 sec
Asymmetrical Shoulder carry -60 sec each side
Cable overhead isometric hold and squat -60 sec each side
Side plank with legs suspended -60 sec each side
Asymmetrical farmers walk -60 sec each side
What would you recommend adding to this for my back? I know that back is a huge area, so I'll say that my upper and lower back, as well as external rotators all need work. I could probably choose a couple of exercises to strengthen them but I don't know what rep ranges/loading/volume to go for and I'm not sure what movements to pick that will work best with the core routine above (or does it matter?).
Also, thoughts on additional exercises I should be doing to maintain what little ability I have would be really helpful. For example, I know its a bad idea to drop leg work altogether, even during a corrective phase like this, but what specifically I should be doing to complement this program is beyond me.
I did try the search but if there's an article I missed or a thread with these answers in it, just point me in the right direction.