In just eight weeks, kids can learn to love activities that improve fitness more than sedentary activities such as watching TV, say experts from Vanderbilt University.

That’s a bold statement, given the facts about increasing rates of obesity and type 2 diabetes in U.S. children. But the researchers can back it up with real-world experience.

Thomas Cook, PhD, RN, an assistant professor at Vanderbilt University School of Nursing, and Barbara Frey, PhD, designed an eight-week program to boost fitness and physical activity in third-grade children.

Why third-graders? They’re young enough to be at the crossroads of lifestyle habits. With encouragement and training, they could find out how good it feels to be active and hopefully develop fitness habits that reduce their future risk of America’s No. 1 cause of death and disability — cardiovascular disease.

Cook and Frey tested their program on 157 third-graders at three elementary schools in Nashville, Tenn. First, they asked the kids about their three most frequent leisure time activities. Almost a quarter (24 percent) said sedentary activities, such as watching TV, reading, or playing video games, according to a news release.

Black children had “the lowest level of high-intensity physical exercises, particularly [black] girls, who are most at risk for cardiovascular disease,” says Cook, in the release.

Next, the students participated in 24 exercise sessions held during physical education (PE) classes three times per week for eight weeks. The 20-minute sessions started with warm-up exercises, such as jumping rope, and included vigorous, noncompetitive games.

After eight weeks, the researchers asked the kids again about their favorite free-time activities. This time, only 16 percent mentioned sedentary activities.

In addition, more than 13 percent of kids who were moderately active before the experiment had stepped up to more intense fitness activities, such as swimming and running.

The researchers assigned a metabolic equivalent (MET) score to each activity; this is a way of measuring the intensity of physical activity. The harder your body works the higher the MET. Any activity that burns 3-6 METs is considered moderate intensity physical activity; an activity that burns greater than 6 METs is considered vigorous intensity activity.

The higher MET increase was seen in the “other race” category, which included Hispanic and Asian students. Their average MET rose by 1.22.

Black students had the second biggest MET increase — an increase of almost 1 MET. White students had the smallest MET gain.

“We found that a short, intense physical activity intervention positively affected exercise behaviors in third-grade children,” write the researchers, who presented their findings in New Orleans at the American Heart Association’s Scientific Sessions 2004.

Importantly, the children enjoyed the fitness experiment. “The kids loved it,” says Cook, in the news release. Ideally, the students will keep their healthy new habits, reaping the benefits for years to come.

By Miranda Hitti, reviewed by Brunilda Nazario, MD

SOURCES: American Heart Association Scientific Sessions 2004, New Orleans, Nov. 7-9, 2004. News release, American Heart Association.