Introducing, Mr. Charles Atlas
If you grew up reading comic books like I did, you probably saw this advertisement somewhere inside its pages:
It's perfect. It plays on your fear of not being able to defend yourself; as though muscles alone will keep you safe!
The photograph of the man in the lower left corner is Charles Atlas who won the title of "The World's Most Perfectly Developed Man."
Atlas said the secret to his incredible physique was a regime of physical exercises that used no equipment, or weights. He said anyone who followed his advice would get the same results.
He sold a mail-order course explaining exactly what to do, and how to do it. Being the curious sort, I bought the course a couple years back and I'm so glad I did.
Turns out, the story of how to do the exercises was more important than what exercises you were doing.
Our bodies work because we have 2 sets of muscles for every joint, basically. One to make it extend out, and one to make it contract in.
Charles said if you flexed both sets of muscles so that they were flexing against each other, you'd get stronger. Imagine you're doing a bicep curl without a dumbell. Instead, you flex your biceps AND your triceps as hard as you can as you move through the motion of the curl.
This is what makes it "dynamic." You're moving through a full range of motion instead of flexing and holding a pose/position like you do with an isometric exercise.
A long time after I'd forgotten about the course, I found a martial arts teacher who told us to run through a series of postures, and make it as difficult on ourselves to move as we possibly could.
After that workout I was sore as I could be. Seems like it worked, after all!
I realized Charles Atlas was using a technique (knowingly or not) that martial artists have been using for centuries. And it makes sense.
The idea is as you work out, you get stronger which provides more resistance, which gets your stronger, and so on with the cycle. Plus, it's incredibly hard to injure yourself because as you get tired, you can offer less and less resistance. It's nearly impossible to overload your system.
People tend to see results for the first couple weeks, but then progress tends to plateau. If you're coming from absolute zero, almost anything you do is going to be an improvement.
After the initial easy gains are made, it looks like you need more than just dynamic tension to build muscle mass, but it's a phenomenal way to up the difficulty of any workout; especially if you're running through a series of postures during your training.