What Makes a "Good" Exercise?
Science, Physics, and Nerd Stuff
I am somewhat becoming like the Grinch Who Stole Your Favorite Exercise.
I have gone on about why bench, deads, and squats are overrated, today (Friday August 26th as of writing this) I went on about pull-ups just not being great compared to other back exercises, and by the time I send this I’ll have probably bitched about some other exercise too.
Why am I like this?
Well, because I have turbo autism and am obsessed with doing things in the most optimal and efficient way and “why” and “how” we do the things we do. Hence many things we do in the gym are just simply outdated and archaic and we can do things much better to get much better results.
In short, it’s because I care, okay?
So don’t shoot me, I’m just the messenger and if you listen you’ll probably thank me when you make more progress and are hurt less often.
Anyway, let’s get into the why and what leads to these critiques—what actually makes an exercise effective and “good”.
What Makes a “Good” Exercise
Being able to load up a bunch of weight and doing something that uses your entire body doesn’t mean the exercise is even remotely effective for your desired outcome, which if you’re reading this I’m assuming is building muscle and getting jacked to the gills.
Quite contrary, this can actually mean an exercise is wildly ineffective and we could’ve done something much more effective with probably a lot less effort and risk of injury.
We’re after results, not ego satisfying, and speaking from experience, results satisfy the ego much more than lifting some large weight on some exercise (you are being outlifted by some female somewhere anyway).
Instead, we will allow biomechanics and physics to guide us as to what exercises are going to be the most effective in the gym.
Before Even Started, Acknowledge This:
The first thing we must acknowledge is that no matter how cool or sexy lifting is, it’s simply a matter of physics. You are lifting a weight, which is producing force on a muscle, which is going to force the muscle to have an adaptive response in order to overcome the challenge in order for its perceived survival.
Let’s get a little Einstein-y up in here!
Every single lift follows this equation: F = M x A
F - Force
M - Mass of an object
A - Acceleration
Within this, we have what are known as levers—essentially these are your limbs or anywhere where we have a joint. These levers will determine the magnification of the force on the muscle.
This further breaks our equations down to this: R x RA = F x FA
R - Resistance
RA - Resistance Arm
FA - Force Arm
F - Force
To further understand this, no book is better than “The Physics of Resistance Exercise” by Doug Brignole, where he further breaks this down in much more words than I can fit into a post + explains it much better (and I won’t steal his work).
It’s not important to understand this in detail if you’re not interested—this simply breaks down the fact that the weight in our hands or on the bar is not necessarily acting on the muscle with that specific force.
Even though we might only have a 10 pound dumbbell in our hands, depending on the exercise and magnification due to your levers, the force placed on the muscle could be 25x that weight, so 225 pounds instead of 10 pounds.
So weight is just a tool and what really matters is how well it loads the target muscle. This is it, some exercises, for reasons we will discuss, do this better, some less efficient, but this is the biggest take away—it is just a physics equation at the end of the day.