You are a machine. You are the descendant of ancestors that were the most efficient at surviving in their environment. Ever since the dawn of predation, surviving requires the ability to move around to escape predators or chase after prey. In order to move around, our ancestors developed a specialized type of cell with many sections called sarcomeres.
The image to the right shows the structure of a sarcomere with pairs of proteins that pull on each other when the cells receive a signal from communication cells. Those specialized types of cells are called muscles.
We’ll start by looking back at our earliest ancestors to have both muscles and bones: our evolutionary grandparents, the fish. Fish are some of our earliest vertebrate ancestors and they moved by contracting muscle on either side of the spine to flap their back fins.
Muscles can pull but they cannot push. If a fish contracts the muscles on its right side, it cannot push the right muscles back into place. Instead the muscles on the left side contract and the right muscles can relax. These two muscles are called antagonistic pairs and they are the basic mechanism for all muscular movement among living things.
Try it out with your own body: move something and focus on which muscle is contracting. Move back to normal and see which muscle contracts while the first one relaxes.
As animals began to populate the land, a need for stronger muscles presented. As you know, fish live in water and being made up mostly of water meant that they didn’t need to exert much contracting force to move around. Without the buoyancy of the surrounding water, the first amphibians and reptiles developed denser muscles with a string-like structure. Remember, this was a random mutation that turned out to be advantageous.
If the sole purpose of muscle cells is to contract, then a string is the perfect shape to best utilize the contracting abilities of a cell. Strings bunched up to become stronger in mammals as the stringy structure proved to be the most efficient method to move the organism around while still providing support to hold it up.
You can see the differences between different types of muscle and compare their relative strengths when you are eating meat. Another name for muscle is meat and you can compare the flaky texture of fish with the slightly stringy texture of chicken, a descendant of dinosaurs, and compare both of those to the very stringy texture of beef, a mammal. The more force a muscle needs to exert for the living organism, the “darker” the meat. It’s scientific and delicious!
Let’s now go into a bit more detail about our muscles in particular. If you look at one of your muscles, well without the skin, you see the strands that make it up. When we look a little closer at these strands, we can see even smaller strands that make those up. When you contract your muscles, especially against a large force, some of those tiny strands, called myofibrils, are bound to break. That’s okay because your muscles have hundreds of muscle fibers, each with hundreds of myofibrils.
When your muscle breaks, your body will repair it but this time will add in some extra lipids and proteins to make sure it doesn’t break again. If those muscles are used repeatedly, your neurons will tell some of the muscle strands to constantly contract to make the movement easier. This is why your muscles get bigger: it is your body’s defense against further damage. It’s also why you need to schedule in recovery days when you work out intensively.
If a muscle does not get regularly worked, fat will be reallocated to the area the muscle should take up. When muscles are left unused for long periods of time, the neurons connecting them to the motor center lose some connectivity and it becomes harder to receive signals. It’s important to regularly stimulate all the muscles to keep connections with them and stay in anatomical form.
Your neurons are the communicators of your body and you can tell a muscle to contract by sending a signal to it. However, you have other neurons that detect the position of your muscles in order to get a better awareness of your body. These neurons are called proprioceptors and they are some of the least utilized neurons that you have.
At some point, I want you to stand up, close your eyes and really focus on feeling exactly where your body is. Maybe you just want to focus on one part or maybe you can feel the whole thing. You can actually start to see yourself from a third person perspective because you can feel exactly where your muscles are and create an image in your mental plane.
Just like all other neural paths, it takes time and practice to master the connection to your proprioceptors but it is well worth the time you put in. If you can see your body as a machine, one that can bend in specific ways, you can detect which muscles are best used for which actions. Take some time to explore your body, stretch around and feel which muscles are uniquely responsible for each movement.
In our sedentary society, we develop connections to the wrong muscles for our movements and we get stuck that way. Slouching shoulders, forward neck, and a weak lower core are now common. When you take the time to discover your muscles, you can learn to massage them along the direction of the strings. You’ll discover parts of yourself that you never realized you had. You can change your body, it just requires the focus and effort to do it.