NEW YORK (Reuters Health) - U.S. kids are not only too heavy; they're also out of shape, according to a new study of 5th and 7th grade students in Georgia.

Half didn't reach minimum standards for healthy aerobic fitness, Dr. Kenneth E. Powell, a physician in private practice, and his colleagues found, while neaTechnorati Tags: kids, unfit, aerobic fitness, overweightrly a quarter didn't make the grade in terms of muscle fitness, endurance or flexibility.

Powell and his team determined body mass index (BMI) and tested fitness and physical activity levels of 5,248 students from 93 schools across Georgia.

They found that 30 percent of the students were overweight -- their BMI was outside the healthy range -- and 22 percent didn't get the recommended 60 minutes a day of moderate to vigorous physical activity.