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The Forgotten 40%

Muscle serves with it several functions and when we take a deeper look into our bodies functions the benefits of muscle mass become more apparent than just the visual benefits that often serve as motivation for an active lifestyle. The muscular system is composed of  around 650 muscles and three main groups, skeletal muscle, smooth muscle, and cardiac muscle all of which play an important role in our bodies every day functions. Skeletal muscles are our bodies only muscles that we consciously control. These muscles flex and contract to manipulate the bones they surround causing the movement we use in our everyday lives. Smooth muscle lines vital organs within our digestive track and blood arteries to ensure both digestion and circulation are maintained. Finally, cardiac muscle found in our heart utilizes the nervous system to regulate our heartbeat and pump blood throughout the body. The main functions our bodies muscular system is responsible for according to Medical News Today in a publication reviewed by Gregory Minnis Doctor of Phyiscal Therapy are:

  1. Mobility 
  2. Stability 
  3. Posture
  4. Circulation
  5. Respiration
  6. Digestion
  7. Urination
  8. Childbirth
  9. Vision
  10. Organ Protection
  11. Temperature Regulation

Our bodies muscular system consist of three main groups. First, skeletal muscle are our bodies voluntary muscles that we actively control to move our bodies and help protect important organs and bones. Our bodies have two main types of skeletal muscles classically categorized as red and white fibered muscle or type 1 and type 2 but more traditionally referred to today as slow twitch and fast twitch fibered muscle. This categorization is due to the amount of myoglobin found in the muscle fiber which is a protein containing iron that serves to transport oxygen in our blood. Type 1 or slow-twitch muscle fibers have both high amounts of myoglobin and mitochondria, which provides energy to our bodies on a cellular level.  This along with the capillaries that surround the muscle fibers, allow for the slow-twitch muscles to perform for longer amounts of time at a submaximal level. Fast- twitch muscle fibers, much larger in size are able to produce greater amounts of force at a level much more quickly than type 1 fibers resulting in quicker fatigue.  The ratio of these muscle fibers differs from individual to individual and can be catered depending on any persons needs with specific training. 

Smooth muscle, the second component of our bodies muscular system is present throughout our bodies in the walls of organs, including our intestines and stomach along with our bodies arteries and veins. These muscles work automatically throughout the day and night to perform functions our bodies need to perform normally. These functions include digestion, urinating and even pupil control found within our eyes. Smooth muscle is a form of non-striated muscle tissue making it optimal for its internal locations throughout our bodies.

Finally, the third part of the bodies muscular system is cardiac muscle. Cardiac muscle is primarily what makes up the middle layer of the human heart and can only be found in this single location. Cardiac muscle is also the only muscle in our body that works without rest, as it is responsible for pumping blood through the heart’s atria and ventricles and into our bodies. Our hearts work so efficiently that on average we pump 2,000 gallons per day.

     Our muscular system makes up for roughly 40% of our total body weight. Even if this number fluctuates between individuals because of their overall body composition, muscles account for a large portion of every persons total body. Keeping this in mind, it becomes clear to see why maintaining a healthy muscular system is important.