Pavel goes on and on about contracting the muscles in the body and utilizing as much of your muscle mass to move any weight, be it yourself in a bodyweight only exercise, or lifting a kettlebell.
This is a very subtle and fine point that needs your constant attention and extension of bodily awareness.
I find now that as I try to move heavier and heavier weight, I need more and more focus when I am moving through the exercise, maintaining awareness of how my whole body is being recruited to assist in the movement. Up until recently I have never realised how the various parts of my body assist each other- thanks to isolatory exercises, and I havent been able to put the whole picture of what my body is doing together in my mind.
Those days are over. The main thing now is that when I put my total concentration on what is happening, my body works a lot harder, and my chances of injury become a lot less. Nowhere is this more obvious than with the Turkish getup, which is a gut wrenching physical statement of raw power and control, taking a heavy weight from ground level and suspending it above your head, then slowly bringing your whole body behind it and up to a full standing position, and then back down again. Three reps back to back with the 20 kg kettlebell on one leg and I am panting and pumped!