Fitness programs in schools help to get children moving, but experts say more is needed to curb rising obesity rates.

Instead of low intensity aerobic exercise, which dominates most school programs, Frederick Hahn, the author of the new book "Strong Kids, Healthy Kids," believes the emphasis should be on strength training and eating the right foods.

"All kids need to let off steam," he told Reuters. "But almost all the so-called fitness programs for kids are wrong-headed."

Hahn, co-founder of the National Council for Exercise Standards, wants to equip school gyms with exercise machines and dumbbells. He said strength-or resistance-training combined with a low-carbohydrate diet is the most effective way to battle childhood flab.

"Strength training is exercise 'concentrate.' You can use a lot less of it," said Hahn, an exercise trainer for 20 years.

According to his book just 30 minutes per week of resistance training will increase muscle mass and speed metabolism in children. Physical activity alone is not enough to prevent obesity in children, he added.

A recent review of 26 studies of school-based activity programs for 6- to 18-year olds in North America, South America, Australia, and Europe, appears to support his thesis.

"It is a must that physical activity be a regular part of the (school) day," said Dr. Maureen Dobbins, of McMaster University in Ontario, Canada, who led the review team.

But Dobbins said her findings, published online by the Cochrane Library, showed school-based activities were not effective in getting kids to be more active outside of school.

"Other activities are needed," she said.

Even more troubling, the review showed that school-based programs had little impact on weight control.

Obesity among children aged 6 to 11 has more than doubled in 20 years, going from 6.5 percent in 1980 to 17 percent in 2006, according to the U.S. Centers for Disease Control. The rate among adolescents aged 12 to 19 has more than tripled.

Dr. Wayne Westcott has helped to bring strength training programs to some 30 public schools in the Boston area. Fitness research director for the South Shore YMCA in Quincy, Massachusetts, Westcott has also served on the President's Council on Physical Fitness and Sports.

"There is no change in body composition without strength training," he said. "I think strength training is the missing component in our school programs."

But for Diane Gallagher, the missing component is dance.

A New York City school teacher with a degree in dance, Gallagher takes her love of movement to public school children in Manhattan through a government-funded enrichment program.

"(New York City) public schools have gym only once a week," she said, "so that is where it is needed the most. The kids get some exercise while having fun."

Gallagher, whose own dancing career has encompassed the styles of modernist pioneer Isadora Duncan and burlesque queen Ann Corio, works with children from kindergarten through fifth grade.

"I use a variety of music from swing, Broadway musicals, even a little James Brown and Beach Boys," she said. "My goal is to introduce kids to the pleasure of dance," Gallagher said. "There are no wrong answers in dance."

And there are very few fat dancers.