North Hall Middle School students showed off their best dance moves at the back-to-school dance social Thursday afternoon.

But 50 sixth- and seventh-graders grooved toward the center of the dance floor with a surprise up their sleeves.

“They cued us and turned the lights on us and we jerked off our jackets and things and we pulled off a true flash mob for fitness,” said Debbie Wiley, physical education and health teacher.

The students revealed matching T-shirts that read “fitness rocks” and performed a choreographed dance inspired by fitness routines.

The students practiced their surprise dance routine in their PE class for the last three weeks.

C.J. Chester, seventh-grade student, said he was a little nervous about the flash mob.

“But then I also thought it was going to be awesome because we just got to be our own selves,” C.J. said.

The other students must have thought it was awesome, too, because they all joined in.

Hall County Schools is participating in Georgia SHAPE, a program that aims to improve the health of students.

Through SHAPE, students are periodically given fitness assessments.

North Hall Middle is one of several Hall schools to be recognized for its achievements with the SHAPE program.

“We’re one of the governor’s gold schools. ... So we want to keep doing things that show up the fact that you’ve got to be active and you’ve got to have a healthy diet,” Wiley said.

Wiley said she’s also incorporating activities and lessons from NFL Play 60, a program that encourages children to be active for at least 60 minutes a day.

Several of the students have formed a Student Wellness Council. They meet regularly to discuss the ways they can continue to make the school a healthier place.

She said the students have reacted positively to the health lessons. Some students have reported losing weight after increasing their activity and making healthy food choices.

Christen Barnes, a seventh-grader, said she has noticed that she feels better since the school year started. She said a lot of her peers are feeling better, too.

“They all want to get healthy and stuff, but sometimes they just don’t take the initiative. But I think this year they have,” Christen said.

C.J. said he’s noticed a lot of his friends getting apples from the lunch line instead of chips.

Every week, Wiley gives her class a goal. Last week, she showed the students how much sugar from soda the average person drinks in a week.

C.J. said he’s made it a point to cut down on the number of sodas he drinks and has seen a difference in his basketball game.

“I don’t get dehydrated, and I can keep playing longer and I can run a lot faster. I do a lot more things now,” C.J. said.