(CNN) You've heard it before, but the message is still urgent: One in four US adults sits for more than eight hours a day, according to a new study from the US Centers for Disease Control and Prevention. Four in 10 adults do not exercise to either a vigorous or even moderate degree each week, the analysis also reveals.

Add to that, one in every 10 Americans reports both behaviors -- sitting for more than eight hours a day and being physically inactive -- according to the study, published Tuesday in the medical journal JAMA.

"Both high sedentary behavior and physical inactivity have negative health effects," the authors of the study said. "And evidence suggests that the risk of premature mortality is particularly elevated when they occur together."

"If you sit a lot at work, for example, then you should try incorporating more physical activity during the week to offset that sitting time," suggested Emily Ussery, lead author of the new study and an epidemiologist at the CDC.

Ussery and her colleagues used data from the most recent 2015-16 National Health and Nutrition Examination Survey of about 5,900 adults as the basis for their analysis. This survey is unique in that it combines both interviews and physical examinations of all the participants.