This is part of a series of posts I'm doing on what I consider my core understanding of how the body works and how to strengthen it.
You Can't Fix A Problem By Loading It
Occasionally people take the approach that heavy weights iron out problems. The idea is, if you have weaknesses, loading will demonstrate those weaknesses and fix them. Weak arms holding back your pullups? Pullups will show that and fix that. Weak core holding back your plank? Planks will show it and fix it.
This can be done consciously, or unconsciously - your running is weak, so you run more. Your bench press fails at 225, so you do 225 until you succeed. Your squat hurts your knees, so you figure you must squat more until you've got it down. It's the "no pain, no gain, so pain must mean eventual gain" approach.
My feeling is that loading reveals problems. It shows you where the weak point is. But then, it gives you a chance to deal with that weakness in another way. Pain, weakness, and failure are your body showing you that something is wrong that must be addressed. But you can't address it with more of an incorrect movement pattern.
Loading has a value in strengthening good movement, and in revealing where you are compensating to create the illusion of correct movement.
Corollary: Fix, then Strengthen - with any movement pattern, from a squat to standing up straight, you want to practice correct movement. If your movement pattern is incorrect and you load it and train it, you will train in that movement. You will cement in that incorrect movement pattern, with compensatory movements included to allow you to perform something close to that movement.
The goal is correct, healthy, and strong movement. First, you must get the body moving correctly. Then you load that movement. If the movement begins to break down, you must analyze why (weakness overall, weakness in a specific area, injury, etc.) and then start to address that weakness. You can't just plug away at the limited movement with heavier and heavier loads (or longer and longer loads) and wait for it to correct. Only repeated correct movement will be successful in getting you stronger and healthier for the long run.
In other words, you can't get better and stronger at something before you can do it right. Once you can do it right, you load it to the point where you can still do it correctly, and then get stronger from there.