Flexibility Tips

How does a person get so flexible he can kick his leg over his head?
How can people do splits?
How can someone who lifts weights have the flexibility normally associated with yoga masters or gymnasts?

Those questions all have the same answer. Let's take a look at it. To maximize flexibility, you need four things:

Genetics. 99% of humans possess the genetics to be highly flexible.
Knowledge. You have to know how to stretch. Many stretching movements actually tear the muscle fibers, resulting in tough scar tissue.
Determination. If you want to be flexible, you will be--provided you work at it.
Time. It takes a very long time to be flexible.

Age is also a factor. Younger bodies are simply more conducive to stretching. However, age does not preclude you from being flexible. Many martial arts masters are flexible well into very old age.

Let's look at benefits, caution, knowledge, flexibility and nutrition:

Benefits

Good flexibility is critical for high performance sports like climbing, martial arts, dancing, and even sex. Proper stretching helps get nutrients into the low-circulation connective tissue, and it helps keep joints aligned properly. Further, it allows muscle growth by enlarging the muscle sheath.

Caution

There is a trade-off between flexibility and stability. You'll have to find your own "sweet spot" there, but generally you will know you are too flexible when you start having pain in weight-bearing joints. If that happens, simply reduce your stretching limits.

More about flexibility, below....

Knowledge

Let's now address the knowledge portion of maximizing flexibility. You can choose from many exercises. It would be pointless to try to describe them all in text. You surely know some already. However, applying the correct principles of stretching will allow you to benefit from those exercises rather than injure yourself.

Stretch gently. Never force a stretch. Doing so damages muscle fiber, and may even tear connective tissue from the bone. You haven't felt pain until you've felt that.
Don't bounce. Yes, some folks do get decent results with "dynamic stretching." However, this is risky and you are better off just taking your time to reach your flexibility goals.
Hold a stretch for 45 to 60 seconds, then relax the part being stretched. If you alternate one minute of stretching with one minute of rest, you will see much faster results than doing one long period of stretching. And, it won't hurt as much.

Stretching and nutrition

You need these nutrients to increase flexibility:

Water. Drink at least 1 gallon (4 litres) of water per day per 150 lbs of body weight, if you are working in increasing your stretch limits. You will need this to keep your cells flushed and to improve general metabolic processes.
Vitamin C and a B complex. Don't take plain ascorbic acid--your body can't absorb it very well. You need B and C together to increase your cell wall elasticity. Begin a B and C regimen at least two weeks before starting to increase your stretch limits. Don't go overboard on this stuff, either--take the recommended dose. Adding vitamin E and essential fatty acids will also help.
You need quality protein to build up cell walls after stretching.
Unless your joints are healthy, you won't have flexibility or mobility without pain.