I thought I'd give this subject a shot myself, seeing as it's cropping up a lot in fitness lately.
Well, of course, we all want to become better at natural human movement. But this begs the question 'what is natural'. Is jumping rope 'natural'? Is squatting hundreds of pounds 'natural'?
Well, yes and no. Squatting is one of the range of natural human movements. Crossfit and the like talk about 'functional movement'. But it's surprisingly hard to argue that the squat, the king of exercises, is totally 'natural'.
What am I talking about? Well, how many times do you, in your regular, non-lifting life have to load a weight on your back and squat it? Not many. Mostly, you either have to deadlift or clean. But the squat unquestionably produces excellent gains. I'm at a risk of overplaying my case here, because you can't very well not squat- a trip to the toilet on a day when you're sore from squatting will prove this. But most of these movements are not loaded. I've seen my workmates and observed myself 'squatting' weights like cement bags and so on, but most of these are of the front squat variety.
So why is the back squat considered one of the best exercises? Could it be that we're talking about a different category of movements here- movements not recommended as a mimicry of natural movements, like some sort of 'tonic' that contains substances you wouldn't usually ingest, but which is designed to be helpful to your body? The bench press falls into this category as well- although if you've ever had to lift a motorbike off you after a crash, the bench press suddenly becomes very 'functional' indeed
The other point is the weights involved. When you're working, the weights you have to lift are negligable compared to what you squat and bench. Really. A cement bag is nowhere near as heavy as a loaded barbell. But the additional weight has a powerful 'tonic' effect on the body, releasing neuroendocrines and subjecting the muscles to considerable tension.
The point is that 'natural' movement can be overemphasised. Jumping rope is something you'd never naturally do, but it's a great warmup and a cool cardio tool that you can take anywhere.
I'm not arguing that natural movements should be ignored. The case that comes to mind most is running. Running is, arguably, what humans are designed to do. The pronounced achilles tendon, the sweating mechanism, etc. etc. all point to this. And it's one of the best cardio exercises.
I'm not talking necessarily about exclusively long, slow running either. Sprints are arguably more 'functional'. I need to clarify a bit here. Arguably the oldest method of hunting is the 'endurance hunt'- prey is literally chased until it reaches the point of exhaustion. So humans certainly do a certain amount of long, slow running as part of their natural activities.
But any comment about what is or is not 'natural' needs to be qualified. For one thing, stone age hunter gatherers did not necessarily do the same things as modern hunter-gatherer societies. For another, if you look at the physiques of the people who go in for this kind of hunting, they're always kind of emaciated and elongated. Not something you'd necessarily want to copy. Also, humans in modern societies who go in for long distance running at the expense of weightlifting and other more strength-based activities tend to be weak. Very weak. We're talking about a vertical jump of no more than a few inches.
It's also pointless to argue over 'HIIT' and 'LSD'. For one thing, I despise marketting gimmicks. 'high intensity' is a tag-on marketting gimmick to make running look like a new exercise. For another, the boundary is not as clear as people imagine. Run up a hill? You just did an interval.
So what's the take-home message? Well, I'd say it's to stop worrying so much about what is and is not 'natural' or 'functional', and concentrate on what is effective