Updated

A group of students in New York will soon be wearing controversial electronic monitors that allow school officials to track their physical activity around the clock in a bid to combat obesity.

The athletics chair for schools in Bay Shore, N.Y., ordered 10 Polar Active monitors, at $90 a piece, for use starting this spring. The wristwatch-like devices count heartbeats, detect motion and even track students' sleeping habits.

The information is displayed on a color-coded screen and gets transmitted to a password-protected website that students and educators can access.

The devices are already in use in school districts in St. Louis and South Orange, N.J., and have raised privacy concerns among some parents and observers.

But Ted Nagengast, the Bay Shore athletics chair, said, "It's a great reinforcement in fighting the obesity epidemic. It tells kids, in real time, 'Am I active? Am I not active?' We want to give kids the opportunity to become active."

In the South Orange-Maplewood School District, where earlier versions of the devices have been used for two years, upper-grade students' marks in physical education classes are based in part on heart-rate monitors and activity sensors.

Teachers use handheld computers to collect data from each student's wrist monitor during class, then upload the information to the school computer system for storage and long-term tracking.

But privacy advocates and parents worry that schools are using electronic monitors in phys ed without families' knowledge or consent.

Click here to read more on this story from the New York Post.