Metro

Beyonce moves ‘em (video)

All the single ladies — and a few guys — were in for a big surprise yesterday when superstar Beyoncé showed up at a Harlem school to help whip them into shape.

Students at PS 161 were in the middle of a choreographed routine — being danced, appropriately, to a Beyoncé song — when the “Single Ladies” singer strode in and stole the show.

The students were participating in a nationally simulcast “Let’s Move Flash Workout” as part of First Lady Michelle Obama’s fitness campaign.

Public and middle schools around the nation took part in the effort, beginning at 1:42 p.m. Eastern time.

The workout was a pre-choreographed dance/exercise routine performed to a song adapted from Beyoncé’s hit “Get Me Bodied.”

POPWRAP: WATCH MICHELLE OBAMA DO THE RUNNING MAN

“She’s beautiful,” said seventh-grader Aisha Collier, 13. “I kind of messed up a little when she showed up but I got back into it. And then I just continued to dance, having fun, having more fun because Beyoncé was there.”

Eighth-grader Shaniya Garcia, 14, said she got a big hug from the big star, and could still smell Beyoncé’s scent on herself.

“I had a feeling she was coming,” Shaniya said. “I wanted to stop dancing, but I couldn’t. I was so excited.”

Beyoncé, decked out in stiletto heels, skinny white jeans and a white tank top reading “Let’s Move,” danced across the school gymnasium.

Her backup dancers, 85 students in black “Let’s Move” T-shirts, did their best to keep up.

The Harlem students said they were crazy in love.

“Outside I was having fun with her,” said Genesis Sanchez. “But inside I was yelling, ‘Ahhhhhh, a famous person had time to come and be with us.’ ”

Schools Chancellor Dennis Walcott and Health Commissioner Tom Farley were also there, but students were a bit less excited about seeing them.

Meanwhile, Michelle Obama herself visited a Washington middle school for the event.

She did the “Dougie” with students at Alice Deal Middle School, where students cheered on the first lady of fitness.

Students were warming up to the Black Eyed Peas song “I Gotta Feeling” when Obama took the stage. As students began to recognize her, they screeched with excitement and rushed the stage.

ikimulisa.livingston@nypost.com