A new school exercise program that replaces competition with individual tests and health education could reverse the decline in fitness among American children while helping them avoid injury, experts say.

The American College of Sports Medicine is just starting to promote the program, called Fit Youth Today, or FYT, which was developed with the support of the American Health and Fitness Foundation in Austin, Texas."It is state-of-the-art exercise science put into a workable form for educators," said Wiliam Squires, professor of health fitness and nutrition at Texas Lutheran College and chairman of the task force that developed FYT.

Unlike conventional school athletic programs, FYT does not favor naturally gifted athletes. It rewards each student for attaining his or her own fitness goals, whatever the level of athletic ability, said Squires.

"The FYT program represents a real departure from traditional fitness testing in this country," he said at a recent symposium here. It includes an educational curriculum intended to teach students about the importance of maintaining physical activity throughout life.

Less than 50 percent of American children have adequate heart-lung endurance, and 40 percent of those 5-8 years old have signs of elevated blood pressure, obesity or elevated cholesterol - all of which increase the risk of heart disease, Squires said. "The decline in youth fitness is real and is overwhelmingly supported by study after study."

The consequences could be disastrous, he said, citing a study reported by the U.S. Centers for Disease Control last year that concluded lack of exercise was as strongly linked to heart disease as smoking, high blood pressure and high cholesterol.

In conventional programs, students are often measured against norms set by their peers. FYT conditions them not to run faster or jump higher than others but to be able to jog a set distance in 20 minutes, perform certain exercises demonstrating strength and flexibility, and reduce body fat specified levels.

The key point is that the goals emphasize aerobic fitness, strength and weight loss - not maximum performance, Squires said.

Carl Caspersen, an exercise physiologist and epidemiologist at the CDC in Atlanta, said FYT's success will be measured by "how well it motivates changes in behavior and guarantees an active lifestyle.

"It is the physical activity we're interest in, and if the testing encourages activity, that's what we're trying to achieve."

FYT also is designed to avoid athletic injuries that can have more serious consequences in children than they do in adults.

Children are unusually susceptible "overuse injuries," said Dr. Lyle Micheli, an orthopedist and director of the Division of Sports Medicine at Children's Hospital in Boston.

These occur when joints and bones with soft growing surfaces are repeatedly subjected to small bumps and stresses, which may alone be painless but can add up to significant damage after prolonged exercise without proper training and conditioning.