More than 900 students at Creekside Elementary School got to help in an attempt to break a world record on Wednesday.

As part of First Lady Michelle Obama’s “Let’s Move” campaign, she led an effort to break the Guinness World Record for the number of people doing jumping jacks during a 24-hour time period.

The event began at 3 p.m. Oct. 11 and ended at the same time Oct. 12. More than 20,425 people were needed to set a new record.

The children did jumping jacks for one minute in their physical education classes.

“It’s something where we can get all the kids together for a common cause,” said physical education instructor Erik Johnson. “They’ve really liked it, so it’s been fun.”

All day long, students covered their mouths in excitement when Johnson told them what they would be doing during his class. After a countdown, the children enthusiastically moved their arms and legs back and forth for one minute.

After the jumping jacks were over, however, Johnson made sure to insert the boring part — to explain that jumping jacks help build cardiovascular endurance and fend off childhood obesity.

“Who can tell me why it was important we did jumping jacks?” he asked.

“So that way our body can be healthy,” student Makeda Price said.

“When you were doing jumping jacks, were you breathing harder?” Johnson asked.

The students answered with a chorus of “Yes.” “Was your heart beating faster?” he asked. Another resounding “Yes.”

Obama kicked off the effort on Tuesday on the White House lawn, with hundreds of Washington, D.C., schoolchildren in attendance.

The official numbers aren’t in yet, but with at least 900 participating at Creekside, and many others jumping throughout the world, it seems certain the record was broken.