Threats, strains, stressors — EXERCISES — have two signatures: [LOCAL] + [GLOBAL].
If you really want to drive adaptation, if you really want to mobilize the body, there has to be a big enough global impact.
It's like this.
You're on your back porch for a cookout.
In Situation A, a fly buzzes around your face. It's annoying. You might wave a hand, but, meh.
In Situation B, a wasp buzzes around your face. If you're like most people, you're more threatened than when a fly is buzzing around. You might throw your chair back, dip your head, and scurry away.
In Situation C, a black bear hops over your neighbor's fence and into your yard. You poop your pants and yell, “Yeehaw!” as you break for a clearing, if for no other reason than to have you last words be “Yeehaw!”
You would make for a good news headline at least. “Man killed by black bear, yells ‘Yeehaw!’ before death.”
Your body mobilizes more when the threat is more…threatening.
Why does this matter?
because muscle isn't cheap. It's the mafia, remember? You have to justify the expense. One way to get the body seriously pushing for muscle is to relay a signal that says,
“If you don't build muscle, my survival will be compromised.”
This is why building muscle isn't easy. You have to CONVINCE/COAX/CAJOLE your body it's a good investment. And global threats do this better.
I'm not using the word “threat” as if you're going to die or get injured. I'm talking about the depth to which your body activates its fight or flight response and the information your body extracts from the situation.
Think of the bench press. The bar held at lockout over your throat. Gravity PLUS extra weight is crushing down atop your body. If you went limp, the bar would crash your throat.
You focus…or die. Your body doesn't know you're lifting weights in a controlled environment. It's being crushed by a giant boulder for all it knows.
Now think of a machine bench press. You're pushing weight in the horizontal plane (opposite of gravity). You can go to sleep if you wanted to and you'd be fine. There's no crushing force. No reason to focus.
Sure, you can stress your chest, which is the local hit. But the global “do or die” stakes are gone.
I'm afraid I didn't make my original point.
Your body doesn't know you're lifting weights in a controlled environment.
There's nothing inherently unsafe about barbell and bodyweight training as long as you control the environment (use the right equipment, use the proper safety measures).
You can crush your throat during the bench press. But not if you bench press in a power rack with the safeties at the appropriate height.
Just about every exercise can be done safely, even if you're by yourself. You just have to know how to protect yourself.
Machines are often advertised as a “safer” alternative to barbell and bodyweight training.
And they are, somewhat…
Sometimes the logistics are screwy though, like fact that I’m 6’4″ and (some) machines force me into the same movement pathway as someone 5’2″. That doesn't make sense.
And machines sometimes allow us to do things we wouldn't normally do, like lock our knees out to the maximum when supporting a lot of weight (on a leg press machine). And the videos of people doing this, only to have their knees buckle backwards are uhfqhgurfg[hoieG[erhgrf[ogfag[uofggsdfgfadgfadgafgkioup[8;op5989889
but let's not forget two things.
Your body is used to dealing with gravity all the time. There's nothing unsafe about a vertical downward crushing force on your body.
It's the exact thing that allows your body to move in the first place. (If you don't use it, you lose it.)
You're now slowly increasing this already present stress, which is something your body is absolutely capable of handling as long as you play the tortoise game and not the hare game.
Controlled threat-strain-EXERCISE-stress-danger is the entire point of training. It's what drives adaptation.
Picking a form of training because it's “safer” is sort of like playing a bungee jump video game instead of going bungee jumping.
You're eliminating the “danger,” yes, but the “danger” is the entire point.