Thousands of us in America have a gym membership and slave away in the gym to try and build muscle. But what actually is muscle? Without understanding what is is, you can never hope to truly find the best way to build muscle.
What is Muscle?
Muscle is “a band or bundle of fibrous tissue in a human or animal body that has the ability to contract, producing movement in or maintaining the position of parts of the body” (dictionary.com). In simpler words, muscle functions as the source of motion and power in our bodies. The main responsibility of muscle is maintaining posture, movement of internal organs, and locomotion. The body consists of a lot of muscles, about 650 in total. These 650 muscles account for roughly half of our bodyweight. The elastic tissue known as muscle is a stretchy fibrous material. These fibers are made of fibrils, which make a larger mass, such as the bulge of our biceps. The nerves in our bodies send a signal to the fibers that make up our muscle that command it to contract. The more fibers that are present, the stronger the muscle is.
Different Types of Muscle
Here is a quick rundown of the different types of muscles in our body:
✓ Skeletal Muscles
These striated muscles move the external parts of the body and the limbs. Skeletal muscles give us our shape; cover our bones and our skeleton. They’re attached to tendons that are attached to our bones or directly to our bones. The skeletal muscles contract when we move our head, fingers, arms, legs, faces, eyes, etc.
We control these muscles; they only move when we tell them to. These muscles are constantly contracting at all times. Skeletal muscles maintain our posture, hold our heads up and move our fingers. These muscles keep our bones in the right position so our joints don’t collapse. Around 40% of males and 35% of females muscle consists of skeletal muscle. Skeletal muscles regulate our body temperature by contracting and releasing our muscles.
✓ Cardiac Muscles
These striated muscles are responsible for heartbeat. Cardiac muscles only exist in the heart. These muscles work from when our heart develops in the womb to when our lives end. If these muscles cease working we cease living. Cardiac muscles contract so that blood is forced in and out of the heart.
✓ Smooth Muscles
These muscles are responsible for movements in the intestines, stomach, arteries and organs. These muscles are activated unconsciously. Smooth muscles contract to aid in bowel movement, uterus contractions, pupil constriction, bronchial expansion, and the arrector pili in the skin to make the hair stand up when we are cold and need to retain heat.
How Do Muscles Grow?
After we workout, our body repairs or replaces the damaged muscle fibers. This cellular process fuses muscle fibers together to form new myofibrils or muscle protein strands. In order for growth to happen, these now repaired myofibrils grow in thickness and number. The rate of muscle protein synthesis must be greater than the rate of muscle protein breakdown for growth to occur. A common misconception of the general population is that growth occurs when we lift weights, however, growth actually occurs when we rest.
While we are lifting or “getting swole”, we are getting a pump. The cells of our muscle swell in a restructuring process for growth. Blood rushes to fill the muscle, a process called edema, when we are in repetition. When there is tension on the muscle there will be growth by creating more muscle fibers. In order for muscles to grow, the tension applied must be a greater load of stress than what we’re accustomed to. Lifting heavier weights progressively will allow the muscle growth and strength to occur. This is where our slow-twitch and fast-twitch muscles come into play. Both are being utilized when we are lifting heavily. During heavy lifting, protein synthesis and satellite cell activation occurs.
When we are lifting, we are actually tearing down the muscle fibers in order for regrowth. During a process called hypertrophy, you create hundreds of micro tears in your muscles. This muscle damage causes a release of inflammatory molecules and immune system cells. This is the activation of satellite cells to begin doing their work. This is when we’ll feel soreness 24-48 hours after a workout. Metabolic stress causes cell swelling around the muscle. This process contributes to muscle growth, possibly without physical muscle growth.
Hormones and Muscle Growth
Hormones affect muscle growth by regulation of satellite cell activity. Testosterone and insulin growth factor promote muscle growth. Testosterone increases protein synthesis, ceases protein breakdown and stimulates the other anabolic hormones required for muscle growth. Strength training releases more testosterone and makes the receptors within our muscle cells more sensitive to testosterone. There’s also a stimulation of growth hormone responses due to an increase of neurotransmitters at damaged fibers, which can activate tissue growth.
Rest and Recovery
The most important step in muscle growth is rest. Without proper rest or nutrition you actually reverse the process of anabolic status to catabolic status. Roughly 24-48 hours are needed for there to be an interaction between protein metabolism in the muscles.
You should try and aim for 6-8 hours of good sleep a night. If you’re getting less than 6 hours you are damaging your body’s ability to repair broken down muscle fibers and allow your muscles to grow.
Take Home Message
There is a limit on how much our muscles grow based on age, gender, and genetics, but if you take notice of the information in this article then you certainly have a good knowledge basis for helping your muscles to grow. This is only a brief lesson in the complicated topic of what a muscle is, how it works, and how to make it grow. Use this knowledge and achieve some real muscle growth this year.