A majority of young American teenagers aren't exercising as much as they should, according to the Centers for Disease Control and Prevention.
The CDC combined information from the National Health and Nutrition Examination Survey and the NHANES National Youth Fitness Survey from 2012.
The study found only one in four 12- to 15-year-olds met the recommendations of an hour or more of moderate to vigorous activity every day.
Childrens' health experts say it's concerning that kids aren't active enough at a time when the country is fighting an obesity epidemic.
An estimated 12.5 million kids in America, from ages 2 to 19, are obese.
"Regular physical activity promotes physical and psychological health and improves some aspects of academic performance," the study reported. "Most studies of physical activity in children and adolescents find boys to be more physically active than girls."
The CDC tracks the physical activity of American youth hoping to inform the public for health interventions. Habits formed during youth often remain in adulthood, and physical inactivity as an adult is a factor for many diseases.
Click here for more information from the CDC.