Muscles, everybody has them, a lot of them, as a matter of fact, they make up about 40% of your body weight, and they are what move you around, keep you upright, move your eyes to be able to read each of the lines of this blog post, keep your blood flowing … – in other words, they are what allow you to function as a living being. We have almost as many muscles in our bodies as there are words in this entire blog post! So, for the sake of time, today we are only going to be talking about your skeletal muscles, and what happens to make them grow.
So, as you know, muscles are a vital part of your life, seeing as you work with them every heartbeat of every day, but for some reason, they don’t seem to get any stronger, even after using the same ones every day of your entire life, so how does muscle grow after all? To start, when you decide to use your muscles, it begins a chain reaction. Your brain sends a signal to your muscles using nerves that tell you muscles to contract, creating force to accomplish your goal, but sometimes, when you use your muscles, it will require more force than your muscle normally needs, which creates microscopic fractures in the muscle tissue. But don’t worry! This is the first step towards muscle growth, and it is what will make you sore after doing muscle activity. Once these microscopic fractures are created, your muscles activate ‘Satellite Cells‘ (Myosatellite cells) to begin the repair process. This is where nutrition, hormones and rest do the real ‘heavy lifting’ to create new muscle tissue. Muscle growth can only happen when Muscle protein synthesis (growth) is greater than the amount of Muscle Protein breakdown (muscle decay), which is why protein is such an important thing to include in your diet in order to maintain and increase muscle mass. On the flip side, if you do not activate your Satellite Cells in order to tell you body to maintain or improve the muscles, you will undergo Muscle Atrophy, also known as Muscle Protein breakdown, which decreases muscle in unused muscle groups. This does not mean, however, that it is a good idea to work out every second of every day in order to stop your muscles from decaying, if so, you are just going to hurt yourself. Muscle growth occurs for 24-48 hours after the workout, and without proper sleep and appropriate nutrition, you can cause your body to go into a ‘catabolic‘ or destructive state. Also, during the those 24 -48 hours, your meals (or lack thereof) will have a direct impact on muscle growth.
An important thing to note about this process is that not all people are created equal, and there are many factors that effect parts of the growth process. Certain hormones have a dramatic effect on the effectiveness of exercise. Most importantly are ones that effect the amount that Satellite cells are activated after working out, as they are the only thing that have such a drastic effect on muscle growth, so people who have a condition that causes the Satellite Cells to never be activated will see no muscle growth no matter how much they exercise. Important Hormones that effect this process include Mecho-Growth Factor (MGF), Testosterone and Insulin Growth Factor (IGF)-1, which all have critical roles in the activation of Satellite cells. Genes can also have other effect that allow for more efficient or generally better exercise, so some people can naturally have faster immune reactions (causing muscle cells to be repaired more quickly), better recovery times, less muscle soreness, etc.
So even though some people naturally have an easier time exercising, taking care of your body, and providing it with proper exercise, food, and rest, can allow you to maintain healthy muscle mass and positively effect your life in general, plus, you now know some cool science to look back upon when you consider how to take care of your muscles. Wikimedia Commons