Jared Rydelek, a professional contortionist, knows the value of warming up before he bends himself out of shape. There's always a new position, a new posture I can learn, the 26-year-old said.

Rydelek starts his three-hour training sessions with cardio, followed by light stretches and extensions until he reaches his limit. Then he pushes slightly beyond that limit in an effort to try out new positions.

Stretching his body beyond recognition depends on several factors. Even the weather can throw him off. Cold weather forces him to warm up until he can perform, even if he already did his warm-up exercises beforehand.

As a performer, I'm often at war with my body, Rydelek said. If my flight's delayed and I arrive at the venue and there is an audience waiting for me, they need to keep waiting until I'm ready.

The art of contortion creates nearly impossible feats with the human body where toes wiggle next to ears and backs become like bendy straws, but contortionists like Rydelek say that their extreme acts takes practice and some flexibility, not a freak physique.

Few scientific inquiries into contortionists exist, but the studies conclude that the super-flexible are far from human oddities.

One of the first studies of contortionists came in an 1882 issue of The British Medical Journal and focused on a man capable of dislocating his limbs. He has, by determined practice, obtained isolated control over individual muscles which one is accustomed to see acting in concert, Edmund Owen, surgeon at St. Mary's Hospital, London, wrote. No doubt, the dissociation of contracting muscle is a mere matter of education.

More recently, a 2006 observational case on a 22-year-old female Chinese contortionist concluded that while there were a few minor problems with her spine, there was nothing abnormal about it. Her spine was just exceptionally flexible. Even when injured, contortionists have a wider range of motion than most mere mortals, said Eric Hanson, who co-authored a 2008 study that looked at the spines of five contortionists. It was pretty amazing to see what the body can do, he said.

While natural flexibility can be a plus, those in the profession say training is key, after all, nobody is born a contortionist. Contortion seemed like the natural thing for Rydelek to do after he graduated from the Coney Island Sideshow School in 2005. Part of his start in contortion involved training himself while working in an office job, doing stretches during 15-minute intervals. He took his training - and discipline -- a step further in 2009 when he attended the Beijing International Art School in China for about a month.

Today, Rydelek performs at all types of events for both children and adults, including parties and weddings. My act is pretty clean, he said. PG-13 at its most.

People who work in industries such as the circus profession, for example, note the discipline required of people who practice contortion. It requires a lot of work and regular training but it's not that people break their bodies to get there, said Guillaume DuFresnoy, artistic director of the Big Apple Circus. It's a slow process that's based on natural ability first and a lot of careful work on top of it. And for that they should be respected.

Performers such as Rydelek know the importance of discipline. Not taking one's time - or pushing too hard - can have negative consequences. The worst injury, he said, would be a neck injury. With that in mind, properly warming up the body is vital for a contortionist, the same way it is vital for any athlete.

There is also the matter of nutrition.

The 1882 study also described the diet of Warren, the 34-year-old contortionist: He has forsworn alcoholic drinks.

Rydelek - a tall, slender man -- was raised as a vegetarian. But he noted that contortion is not necessarily about being thin -- it's about being healthy.

Dwoira Galilea, a San Francisco-based contortionist and aerial performer, maintains a diet of mostly fruits, vegetables and protein, but allows an indulgence once in a while of ice cream and chocolate. Not a whole lot of it but I do eat it, Galilea, 23, said.

Like professional athletes, even the best contortionists have an expiration date. Dominique Jando, a circus veteran and editor of the circus website Circopedia.org, notes that contortionists do not usually continue the art past the age of 40. Even many of the great contortionists he's known already started hurting by their mid-30s.

Traveling places extra demands on performers. Galilea, who also does aerial acts, has performed with traveling circuses, which requires that she pitch in with other tasks, including show set up and activities during intermissions. Such work can be time consuming enough without adding in the need to warm up before a show.

There would be days where we would finish setting up so close to show time, she said. Never thought I would not warm up before a show.

While she can perform an aerial act without warming up, she admits it doesn't feel too good. She has heard her bones pop and crack in protest. That cannot happen with contortion. I have to do certain stretches before I go out there, she said. Her fastest warm-up was about 20 minutes long.

There was also the matter of adjusting to space issues, such as warming up in the really tiny trailer she had while performing with a Mexican and Brazilian traveling circus this year. She soon figured something out to make it work. If I can warm up here I can probably warm up anywhere, she thought.

Jando compares contortionists to the ballet. Both are very physical, and there is a certain charisma and technique that sets an excellent performer apart from a mediocre one. It's not enough just to do tricks, Jando said of contortion. It's a profession. It's an artistic profession.

There is also the matter of catering to a specific audience.

I would never go for the shocking because it is too much for our audience, DuFresnoy of the BAC said. It's not a freak show. Instead, what he looks for in a contortionist - and any performer, really -- is a want and a willingness to communicate with the audience, something that not all performers want to do. For us it's really a requirement, he said.

Rydelek wants to take his art to a whole new level. He is going to India in February for training and is seeking a fellow entertainer, someone whose art and skill set can complement his own.

Galilea is open to the possibilities contortion has opened her to. She pointed out the different skills she has gained while on the road, including costume work.

I love it but it is hard, she said of contortion. There are just some days where it's harder than others.

Still, she loves her chosen profession.

It's definitely a special art form, she said. It takes a lot of self-discipline. You really feel your body in a different way.