JUNEAU -- The state is encouraging Alaska elementary schools to take part in a three-month challenge aimed at encouraging kids to be more physically active.

The effort is partnership between the state health department and Healthy Futures, a program promoting childhood physical activity.

Schools have until Jan. 13 to sign up for the challenge, which the department says will run from February through April.

Kids in participating schools will be asked to complete at least 30 minutes of physical activity outside gym class three days a week.

Logs will be turned in every four weeks, and children will receive a prize. The challenge has three four-week periods.

It's part of a department push to raise awareness about childhood obesity and encourage more physical activity among families as a way to improve health.