This is a tough one for me to wrap my head around, so if I go off in a weird direction please tell me.
The more of your body you recruit to do a specific task, the more it taxes the system. So for example, If I lift a spoon off the table with only the muscles of my hand, I am taxing very little of my body. If I use my forearm muscles in addition to my hand muscles I tax more of my body. The more of my body I use, the more taxing it is. Larger muscle groups require more energy from the body.
This is why I said it's not efficient to use the whole body to move a light object. I think we kind of might agree on that, but there is a sticking point here somewhere.
I personally believe that only muscles move the physical body. I know that sounds like a really obvious thing to say, but I want to make sure we're all on the same page. So, if you want to move the body, you'll have to use muscle. The more muscle you use to move the body, the more you will tax the system. The less muscle you use to move the body the less you tax the system.
Now there is a type of training, where we learn to only fire the useful muscles, in only the correct firing order to do the job we need them to do. This kind of training requires all non essential muscles to relax, and all essential muscles to fire in their most efficient order. This gives us maximum muscle recruitment, for only the duration needed, and keeps all muscles that don't need to work in a relaxed state. This type of training makes the smallest tax on the body possible, to achieve the best results possible.
I would call a kind of training like this very efficient, and so with the definitions I was asking about, I would then call this kind of training "internal".
What I get from your post is one of these things:
You believe taxing the whole system, no matter the requirement of force, is a good idea?
Or are you saying that more muscular recruitment doesn't tax the body more?
Or, are you saying that there are ways to move the body that doesn't require muscle?
I'm sure these are all at least kind of wrong, but I'm asking for clarification.
Chris, this example is EXACTLY the opposite way of how you need to look at it, "This kind of training requires all non essential muscles to relax, and all essential muscles to fire in their most efficient order."
Flip this on it's head. Say someone is pushing you from the front. Now, in terms of efficiency, it is most efficient to completely relax the back side, and essentially use the other person as half of a supporting arch, could be a clinch or whatever, for example. If they pull away suddenly, oops, you're now hosed, you will fall forward, however slightly, in that moment. You can react quickly to pull back, but then you're reacting, and while you're reacting to their action, they've already moved on to hit you. And you can react to that hit and while you're doing that they're kicking you and on and on. You're always one step behind. You're always committed, except when you're doing nothing, and doing nothing is not an option.
You must be on everywhere beforehand, so that there's never a reaction. Reaction is too late - it means the other's initiative is dominating you. Half the game is making sure the mind never shuts off to the infinite possibilities of what can happen at any time, despite what your body may incidentally be doing at the time.