Mighty Muscles

Muscles are designed to provide strength and stability to the skeleton in posture and movement. Their range of movement is uncomplicated; from a fixed point of non-activity they either contract and shorten or stretch and lengthen. Depending on their point of origin and insertion (from one bone to another), the joint’s movement will be determined and, depending on the muscle’s size and range of movement (degree of contraction and flexibility), the strength and mobility will be determined.

The energy for this muscular activity comes from two sources: food and oxygen (respiration). Muscles are essentially formed of bunches of fibres (protein filaments) and are supplied by blood vessels and nerves. Nutrients and oxygen are delivered to the muscles via the blood vessels and the activity of the muscle is determined by the communication to and from the brain via the nerves. A muscle does not act without instruction although it often acts without awareness. The instruction is non-specific; you do not instruct your biceps to contract as you pick up your cup of tea, you just think about picking the cup up. In addition, the force needed to pick up a full cup of tea compared to a half full or nearly empty cup will vary so, according to your perception of the required energy needed to lift the cup, your brain will automatically determine the force in the action, based on previous and established experiences.


Actions can be divided into two categories; immediate or dynamic and sustained or endurance, so muscle fibres are designed to provide for either of the two categories according to the skeletal demands. For example, the muscles in the back are mostly involved in maintaining posture so they have more fibres associated with sustained activity, whereas the muscles in the legs are needed to provide more immediate actions (walking and running) so they have more fibres associated with this dynamic activity.

The fibres associated with dynamic or immediate action are known as quick or fast twitch fibres. The force needed to complete the action is varied but immediate and the energy source they rely on comes from food or proteins. This energy source ironically is not immediate as it takes time to ingest and digest and then to convert the proteins into useable potential energy molecules (ATP). This type of muscle fibre tires quickly as it rapidly uses up its available energy source. Therefore it benefits from prolonged stretching to reduce the build up of toxins (wasted/used proteins) and to increase its movement range, which in turn increases its energy/force potential. For this reason it is also the muscle fibre that is most prone to injury in athletes when the force demand exceeds the actual force capacity.

The fibres associated with sustained or endurance type action are known as slow twitch fibres. They have a high respiratory capacity and source oxygen for their constant energy supply. They are most affected when the oxygen levels are disturbed due to altitude or irregular/uneven breathing patterns, which is why it is particularly important for athletes who participate in endurance sports to incorporate a controlled breathing rhythm into their training as it can directly influence their sustained performance levels.


When a muscle is damaged from immediate or prolonged trauma the fibres tear or split in the same way that a bone breaks. Like bones, muscles repair themselves. However, the tissue that helps to bind the damaged muscle fibres together( which is is essentially fibres of collagen)  has less elasticity than ordinary muscle fibres. In addition to this, the fibres literally adhere to themselves and the surrounding tissues, which is why, as part of the recovery process, massage of the damaged area is recommended. Clearly, scar tissue in muscle fibres reduces the energy potential, so stretching is extremely beneficial as it helps to reduce the unnecessary adhesions. Due to the body’s amazing capacity for cellular renewal, the muscle is able to return to a healthy state and recover its performance level.


Whilst performance is judged from the outside, it starts from the inside; the attitude behind the action and the awareness of the action. Most self-inflicted injuries occur through a lack of awareness in the movement. One of the key elements to a Yoga Practice is the mental connection to the body and being in the moment; not having expectations of what the body should be able to achieve, in relation to previous practices, but listening to what is happening right  now. The body can only be in the present moment whilst the mind often runs ahead of itself or goes back to the past, with the body continually playing catch up. Working with the breath encourages the mind to stay in the present and improves awareness in the physical activity, whilst at the same time, improving cellular respiration within the muscles themselves. The enhanced awareness in the action (posture) means that it will be more effective. The posture itself does not DO anything for the body; it is the awareness that the individual brings to the posture that helps them explore the potential benefits of the posture(s) and therefore their practice. Effective stretching leads to muscular potential in terms of force and endurance; it’s a win, win situation.

“It gives me the flexibility and the strength not only to play the game but to train as well”
Ryan Giggs, age 39, Professional Footballer, talking about the benefits of his yoga practice.

Article written by Heather Langley