Everything you do has an impact on your muscles, whether you’re an athlete who lifts three times a week, or you’re more of a couch potato who rarely gets up to stretch. The former will experience muscle hypertrophy, or the growth and nourishment of muscle, and the latter will go through the opposite, muscle atrophy, in which muscle mass diminishes and withers away. In order for muscles to grow, we have to move and put strain on them, of course. But on a molecular level, here’s how it works: This TED video shows how our muscles grow through tiny tears in muscle fibers, immune system repairing, and rest. When you lift something heavy, your brain sends signals to motor neurons in your arms, which activate the movement of your muscles. The heavier the object you’re lifting (or pulling or pushing), the more signals your brain sends, and the harder your muscles work. When they’re under a lot of strain, the muscle fibers then experience tears, tiny damages to the tissue that must be repaired. This is where the magic happens, even if you experience muscle pain or soreness: after lifting weights, often while you sleep, cytokines are released to activate the immune system and repair the tissue. The body then creates even more tissue so that next time you lift something heavy, it will be more prepared to lift it. Of course, your immune system isn’t the only thing responsible for repairing damage in your muscles. Proper hydration, nutrition (especially protein), and sleep are crucial in re-building muscles. We are made up of over 600 different types of muscles, determining about one-third to one-half of our body weight. Don’t let them fall by the wayside from a sedentary lifestyle, rather, nourish them to be the best they can be. Source
