At age 41, Dara Torres is the first American swimmer to compete in five Olympic Games. She is also the oldest female swimmer in Olympian history.

The Meridian Flexibility System, also referred to as Resistance Flexibility and Strength Training (RFST), is a new stretching technique that not only makes bodies like Torres' more limber but also stronger.

"The concept is really simple: resist when you stretch," said Cat Fitzgerald, a certified RFST trainer and director of Hara Health in Coral Gables, Fla..

Unlike regular stretches, which hold muscles in a passively stretched position, RFST actively lengthens muscles by stretching while moving them through their natural range of motion. Many people overlook stretching as a nonessential part of their workouts, but experts say it is the key to maintaining and youthful and healthy body.

RFST was developed by Bob Cooley, who in 1978 was hit by an automobile driving at more than 70 mph. After traditional therapies failed to rehabilitate his body, Cooley turned to stretching.

He came up with 16 stretches -- eight targeting the upper body and eight targeting the lower body. Cooley soon realized each move equated with meridians of traditional Chinese medicine that run throughout our bodies.

"The concept is that there is a concomitance between certain muscle groups and internal organs," Fitzgerald explained. "Sometimes, you might feel something in your hand, but it's actually associated to your liver. Because we do not normally know what our liver feels like -- we have no experience with that in general -- our brain sends it there."

Fitzgerald came across Cooley's book The Genius of Flexibility while browsing in a book store. One piece of information from it struck him in particular: "We are supposed to peak athletically between the age of 35 and 45, which goes contrary to everything we are taught, told and that we see in our own personal experience."

An avid martial artist, Fitzgerald had been suffering from chronic shoulder pain. After several weeks working with Cooley, he was able to pass a black belt test by breaking through four bricks at once with no repercussion to his shoulder at all. Fitzgerald trains four-time Olympian sailboarder Michael Gebhardt as well as Catherine Garceau, a silver medal synchronized swimmer.

Lee Kaplan, M.D., chief of the Division of Sports Medicine at the University of Miami, said RFST may especially benefit older individuals, who have decreased water concentration in their soft tissues.

"Tendons and cartilage can become more brittle, and when they become more brittle, they are more susceptible to injury," Kaplan said.

Older bodies take longer to bounce back, but RFST may speed recovery time. Dr. Kaplan warns, however, not to overdo it.

"There is always danger to over-stretching," he said. "There is always danger in terms of muscle injury and muscle tendon injury, but to do it within a focused concentrated and do it with people that understand what those limitations are and to build up to certain activities is important."