Muscle Fibers! Part 1

The human body is absolutely fascinating. 

The more I learn about my body, the more I want to use it- dance, and jump, do handstands, and lift heavy things!

While studying to become a personal trainer,  I learned so much about how our bodies work, and I was constantly in awe.

Did you know that you have different muscle fiber types? This determines your strength & stamina, and your genetics play a major role! With consistent training, you can absolutely develop your muscle fibers and improve their ability, so don't blame Mom if your a slow runner! (OK, maybe you can blame her a little bit!)

 In your body, you have three muscle fiber types; the white fast twitch, the red fast twitch, and the red slow twitch muscle fibers.  They have the same internal components, in varying number and size!

Each fiber is stimulated to contract by a branch of the neuron called an axon. The skeletal muscle cell fiber consists of several components, each having a specific function.

The contractile components are called the myofibrils. They allow for strength and performance of work! When it's stimulated to contract, they experience a contractile shortening and increase in circumference.  They are comprised of the proteins called actin and myosin, which slide into each other during these contractions.  Lifting something very heavy and slowly will have its primary effect on the actin and myosin in the myofibril!

Mitochondria are known as the POWERHOUSES of the cell, and they are located all along the myofibril! They produce energy aerobically (with use of oxygen) in the form of energy called ATP! The ATP energy is used during contractions- your every day activities, and and recovery needs.
The cells will adapt by building more mitochondria if you partake in regular and intense high rep resistance training (ie. High reps with a lower weight, opposed to a heavy weight with lower reps.)
By training this way, you will improve your cellular energy storage and ATP production capacity!

The muscle tissue cells also contain several nuclei. They are positioned along the entire length of the muscle fiber and are embedded in the Sarcolemma (cell membrane!). The nuclei contain DNA which control all cellular functions and respond to hormonal stimulations from the pituitary, adrenal, and thyroid glands. (The absence of this stimulation would result in inactivity and degeneration of the muscle tissue cell). 

The DNA transfers information! So information goes from the nucleus, to the mRNA housed in the nucleolus. mRNA take instructions from the DNA to the ribosomes. 

The ribosomes are elements that actually manufacture body protein! They occur in the rough sarcoplasmic reticulum (which is located along the entire length of the myofibril components).

Ribosomes are the ASSEMBLY LINE! They build & repair the contractile proteins actin and myosin in the damaged myofibrils using available intracellular amino acids resulting in growth of tissue!

OK, so let's stop right here and call this post Part 1! 

It get's more and more interesting! I personally love learning about my muscles and what they are experiencing, because it motivates me to push through my workouts and embrace the burn!




Sources: 
www.brittanica.com http://www.britannica.com/EBchecked/topic/377106/messenger-RNA-mRNA

www.sportsmedicine.about.com
http://sportsmedicine.about.com/od/anatomyandphysiology/a/MuscleFiberType.htm

NFPT.com
Personal Fitness Trainer. Certification Preparation Manual. Fundamental Theory and Practical Application for the Personal Trainer. VOLUME ONE.

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