In the simplest of terms, flexibility is the ability to move muscles and joints to their fullest potential – their ultimate range – what is also known as “range of motion”. Interestingly, this ability comes naturally to us at the time we are born, but through time and apathy (like many things), most of us tend to lose it. "Our lives are restricted and sedentary," explains Dr. Thomas Green, a chiropractor in Lincoln, Nebraska, "so our bodies get lazy, muscles atrophy, and our joints settle into a limited range. This is a perfect example of “use it or lose it”! 
As time goes on and as we age, if we don’t actively practice our stretching techniques on a regular basis, the muscles, joints and connective tissue of our entire body slowly constricts, becomes dehydrated, and stiffens, kind of like a piece of leather. This leads to a large degree of aches, pains and soreness, and increases the chances of injury performing even the most typical day-to-day activities.
Stretching, which is movement that lengthens the muscles, improves flexibility and function and literally keeps our bodies from drying out by stimulating the production of lubricants. It also increases blood and oxygen circulation throughout the body, gives you better balance and posture, provides a quicker healing time (in the case of those injuries!) and all-around improves your personal mobility - every move you make and every position you find yourself in on a daily basis.
We owe much of these stretching and flexibility benefits to the most important connective tissue that affects our flexibility, which is called muscle fascia, and is the only one, out of three – the other two being tendons and ligaments - that can be stretched safely. Fascia is a sticky, protective matter that adheres to each of our muscles and organs, decreasing friction and stress when the body moves. You can think of fascia as a plastic wrap that ensures safety and protection from harm to our organs, or maybe even a fine, mesh net (safety net, you could say?) that “hugs” each delicate muscle and organ. As a connective tissue, fascia basically helps keep our bodies “put together”, a network connecting all our parts from head to toe.
