Saw the Real Moving yeti!
Great to see two solid groups last friday as we took on the 'on bike gym' and worked in a skills based workouts with resistance muscular work to build muscle
Just a quick reminder before I recap what we chatted about. I am off to a gravel race so I will be gone this Friday, But my amazing Partner Matthew will lead you all on a new and super fresh route and chat about all things bike packing and what he does to get ready for his long 300+ mile multi day Bike Packing ultra Races.
We are going to be easy on him so will will have only one time next week at 7:30am mdt, but I will be back the following week to lead you all into May
*he will be riding as me so you can still see the awesome unicorn sparkles
Now with that, Lets recap the science that we talked about with all things muscles on friday...
Our muscles are incredible machines and understanding exactly how they work will make you really appreciate all the work you put towards to make them stronger. So in those moments you are feeling that uncomfortable pain and are struggling, remember what goes into it and know that your body is incredible and really making the amazing happen.
Lets dive into what it really takes to move our muscles...
Muscle contraction occurs when the thin actin and thick myosin filaments slide past each other.
Actin and myosin are both proteins that are found in every type of muscle tissue. Thick myosin filaments and thin actin filaments work together to generate muscle contractions and movement.
Myosin is a type of molecular motor and converts chemical energy released from ATP into mechanical energy. This mechanical energy is then used to pull the actin filaments along, causing muscle fibers to contract and, thus, generating movement. Muscle is a type of contractile tissue found in animals, and its main function is to facilitate movement. There are three types of muscle tissue found in the human body, and these are:
Smooth muscle – Smooth muscle contracts involuntarily and is found in the internal organs (except the heart) and blood vessels.
Cardiac muscle – Cardiac muscle is found only in the heart and also contracts involuntarily.
Skeletal muscle – Skeletal muscle is attached to the bones. It is the most abundant type of muscle tissue in the human body, and the only type of muscle that can be moved voluntarily.
All three muscle types contain actin and myosin filaments, which work together to produce muscle contractions.
Muscle tissue is made up of bundles of muscle fibers. Muscle fibers are long, skinny cells that can be up to several inches long and, in the case of skeletal muscle, may contain several nuclei. The cytoplasm of muscle fibers contains long, thread-like structures called myofibrils, which are made up of bundles of thick, myosin filaments and thin actin filaments. Surrounding the actin and myosin filaments is a structure called the sarcoplasmic reticulum (SR); a network of tubules that store calcium ions. The SR also plays an important role in transmitting electrical signals. These electrical signals are delivered to the muscle cells by neurons. Actin and myosin work together to produce muscle contractions and, therefore, movement. First, a motor neuron delivers an electrical signal to the muscle cell from the brain. This triggers the release of a chemical called acetylcholine. Acetylcholine causes calcium ions to be released from the sarcoplasmic reticulum. Next, the calcium ions bind to a protein called troponin. Troponin is attached to another protein, called tropomyosin, and is found between the actin filaments in muscle tissue. When calcium ions bind to troponin, the shape of troponin changes. This moves tropomyosin from the myosin-binding sites on the actin filament and ‘unblocks’ them, making it possible for the myosin heads to bind to the actin filament.
Now now that we have a good understanding of what our muscles are comprised of. You might wonder exactly what enables them to fire
How do our muscles actually contract and how are they able to move?
as mentioned earlier...Muscle contraction occurs when the thin actin and thick myosin filaments slide past each other. It is generally assumed that this process is driven by cross-bridges which extend from the myosin filaments and cyclically interact with the actin filaments as ATP is hydrolysed.
Current biochemical studies suggest that the myosin cross-bridge exists in two main conformations.
There are steps to which muscle contractions are enabled:
1- action potential to muscle.
A Muscle Contraction Is Triggered When an Action Potential Travels Along the Nerves to the Muscles. Muscle contraction begins when the nervous system generates a signal. The signal, an impulse called an action potential, travels through a type of nerve cell called a motor neuron.
2-ACETYLCHOLINE released from neuron.
Acetylcholine is stored in vesicles at the ends of cholinergic (acetylcholine-producing) neurons.
In the peripheral nervous system, when a nerve impulse arrives at the terminal of a motor neuron, acetylcholine is released into the neuromuscular junction.
3-acetylcholine binds to muscle cell membrane.
The acetylcholine binds to the nicotinic receptors concentrated on the motor end plate, a specialized area of the muscle fibers post-synaptic membrane. This binding causes the nicotinic receptor channels to open and let sodium ions enter the muscle fibre.
4-sodium diffuse into muscle, action potential started.
The electrochemical gradient across the muscle plasma membrane (more sodium moves in than potassium out) causes a local depolarization of the motor end-plate. This depolarization initiates an action potential on the muscle fiber cell membrane (sarcolemma) that travels across the surface of the muscle fiber.
5-calcium ions bond to actin.
The calcium ions bind to the troponin, changing the shape of the troponin-tropomyosin complex such that the actin binding sites are uncovered. As soon as myosin binds to actin, the cocked head of myosin releases sliding the actin fiber.
6-myosin attaches to actin, cross-bridges form.
This process is known as myosin-actin cycling.
What triggers a muscle contraction?
A Muscle Contraction Is Triggered When an Action Potential Travels Along the Nerves to the Muscles. Muscle contraction begins when the nervous system generates a signal. The signal, an impulse called an action potential, travels through a type of nerve cell called a motor neuron.
What chemicals are needed for muscle contraction?
The contraction of skeletal muscles is an energy-requiring process. In order to perform the mechanical work of contraction, actin and myosin utilize the chemical energy of the molecule adenosine triphosphate (ATP).
Hope you all learned something new that you can take away and better understand your amazing body at work. Now have fun with Matthew and take it easy on him for me 😉
See you all soon!