Fitness levels dive as U.S. kids get older

"These results reinforce the need for early intervention to prevent or delay the decline in physical activity during the early adolescent years," says Yang Bai. (Credit: Wayne Silver/Flickr)

A new study of American schoolchildren in first through twelfth grades finds fitness levels sharply decline as students get older.

Fitness levels varied greatly based on gender and age. For example, the percentage of boys meeting the requirements for healthy aerobic capacity ranged from 62.1 percent to 37.6 percent. Girls ranged from 50.8 percent to 26.1 percent.

Aerobic capacity among boys started to decline in the sixth grade, while girls experienced a continual decline with age, researchers report.

There was less variation among boys and girls with a healthy body mass index. However, researchers say there is room for improvement in both BMI and aerobic capacity.

“These results reinforce the need for early intervention to prevent or delay the decline in physical activity during the early adolescent years,” says Yang Bai, lead author and a graduate research assistant in kinesiology at Iowa State University.

Fitness tests

FITNESSGRAM is a youth fitness assessment tool used in schools. The NFL PLAY 60 FITNESSGRAM Partnership Project, which is funded by the National Football League Foundation and managed by the Cooper Institute, tracks health and fitness data from more than 1,000 schools in the US.

The research team has worked with the Cooper Institute on the coordination and evaluation of this research project that involves schools from each of the 32 NFL franchise cities. The program provides support in the use of the FITNESSGRAM assessment program as well as assistance in helping schools incorporate more physical activity into the school day.

“Physical activity is important for healthy youth development. Schools benefit from creating healthy school environments and to also provide healthy opportunities for the students,” says Greg Welk, professor of kinesiology. “NFL Play60 includes programming, but the real goal is for schools to embrace the broader philosophies and build on it over time.”

More than 192,000 students from 725 schools completed the FITNESSGRAM testing, which includes assessments of aerobic capacity, BMI, abdominal strength and endurance, trunk extensor strength and flexibility, upper body strength and endurance, and flexibility.

Gym class

The percentage of 4th through 12th graders meeting healthy requirements for five or six of the six tests ranged from 20.7 percent to 34.6 percent for boys, and 19.9 percent to 31.5 percent for girls.

In the paper, researchers also point out that only 48 percent of high school students went to physical education (PE) classes on one or more days a week, according to the most recent Youth Risk Behavior Survey.

Bai says this is important to note because the fitness data collected in PE classes may not represent the entire high school population. Researchers plan to examine physical education requirements in future studies.

Additional researchers from Iowa State and the Cooper Institute contributed to the study. The study appears in the Journal of Pediatrics.

Source: Iowa State University