Along with National Geographic, Mrs. Obama attempted to break the record for the most people doing jumping jacks in 24 hours. More than 20,000 people all over the world will participate in the contest, but Washington was the first city to try it.
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NBC's Al Roker hosted the event and Olympic figure skater Michelle Kwan was on hand as an independent witness. Mrs. Obama, dressed in a green shirt with a purple sweater and black yoga pants, helped organize the kids in lines so they could be counted.
"The world is going to see just how much fun we can have not just breaking a world record but also doing some exercise," Mrs. Obama said. "Because that's one of my big things. Let's Move! is about kids eating healthy and moving and staying active, so you all are ready for life and for all the challenges that you're going to face.
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Last week, Mrs. Obama launched a Let's Move! soccer clinic with the U.S. Women's National Soccer Team.
The First Lady and the players taught kids the same drills that are in the National Soccer curriculum to show that exercise can be enjoyable. After Tuesday's jumping jacks were over, the children ran toward Mrs. Obama, screaming and hugging her until the Secret Service stepped in. "I'm never going to wash my hand cause she touched it," shouted one boy.
Guinness will review the challenge within a few weeks to determine if the record was actually broken.