Stretch

Flexibility is related to life, stiffness with death, a newborn baby is supple, flexible and natural, and a corpse is rigid, inflexible and unbending.
Stretching is the most natural activity performed by many animals including human, the fiber muscles need constantly to contract and extends to maintain healthy tissue, muscle tone and range of motion.

Amazing physical changes happen when you improve your flexibility; as you improve in your stretching, your movements acquire certain fluidity; you stand taller and feel more alert. Our body language, muscle memory, strength, and endurance feel stronger, minimizing the risk of new injuries and making possible old injuries to disappear.

The more time you spend stretching, looking inwardly the more sensation of conflict you release in your body and this is reflected in your relationships, a profound understanding of human condition turns into love towards us and the world.

Stretching bring you into the present moment, the past is an illusion nothing we can do about it, the future is just an expectation, the present is the only tangible reality, being here and now bring contentment and peace of mind.

Flexibility determines how graceful you are in your walking, posture, dancing, in every expression of your body language, how fast you instantly react, and flexibility makes you look young and vital.

The muscle can contract the contraction of a muscle does not necessarily imply that the muscle shortens; it only means that tension has been generated. 
Flexibility improves your strength because the contraction and extension of the muscles go together.

Muscles can contract in the following ways; Isometric contraction best example will be trying to push an immobile object, Isotonic when you successfully push or pull an object. Isotonic contraction can be divided in concentric when the muscle shortens, lifting weights and eccentric when the muscle lengthens, lowering the weight.

During a concentric contraction, the muscles that are shortening serve as the agonists and hence do all of the work. During an eccentric contraction, the muscles that are lengthening serve as the agonists (and does all of the work).

Flexibility releases pain, prevent injuries; sometimes with bad postures, we compress the organs, affecting the digestion, peristalsis, and breathing. When the breathing and digestion happen efficiently the immune system is not active, can relax and defend the body more efficiently.
Yoga is one of the examples of how flexibility, breathing, and strengths can affect your spiritual life; you open yourself to goodness and better connection with people and your environment.

Space in your muscles creates space for the prana, chi, or vital energy to move more effective, nourishing your functions.
The oldest exercises in China and India put emphasis in stretching; yoga and Dao-In are based on stretching with the circulation of Chi or Prana through the channels of the body meridians or Vayus, they knew in ancient times what scientific studies are proving today.