http://l2.yimg.com/bt/api/res/1.2/xMv0iQX71GPp05ICWqarfw--/YXBwaWQ9eW5ld3M7Zmk9aW5zZXQ7aD0zNTQ7cT04NTt3PTUxMg--/WASHINGTON, DC - OCTOBER 11: First lady Michelle Obama greets children after doing jumping jacks with 400 school children on the South Lawn of the White House, on October 11, 2011 in Washington, DC. First lady Michelle Obama led local school children in doing one minute of continuous jumping jacks while attempting to help break the Guinness world record. (Photo by Mark Wilson/Getty Images)
http://l2.yimg.com/bt/api/res/1.2/YtN4XX3FfnH6PoJPJOtvUQ--/YXBwaWQ9eW5ld3M7Zmk9aW5zZXQ7aD0zMjc7cT04NTt3PTUxMg--/First lady Michelle Obama hosts local children on the South Lawn of the White House in Washington, Tuesday, Oct. 11, 2011, as they attempt to break the Guinness World Records title for the most people doing jumping jacks in a 24-hour period. (AP Photo/Pablo Martinez Monsivais)
http://l.yimg.com/bt/api/res/1.2/.fdIROV0tO_nV9JIDoPs1Q--/YXBwaWQ9eW5ld3M7Zmk9aW5zZXQ7aD0yODM7cT04NTt3PTUxMg--/U.S. first lady Michelle Obama (C) jumps with four hundred children at an event on the South Lawn of the White House in Washington October 11, 2011 to launch a challenge to help break the Guinness World Records title for the most people doing jumping jacks in a 24-hour period. To break the record, more than 20,000 people from around the world must perform jumping jacks for one minute. REUTERS/Yuri Gripas
http://l3.yimg.com/bt/api/res/1.2/VWHYdBK2mIDliHhtswp_KA--/YXBwaWQ9eW5ld3M7Zmk9aW5zZXQ7aD0zNzA7cT04NTt3PTUxMg--/U.S. first lady Michelle Obama jumps with four hundred children at an event on the South Lawn of the White House in Washington October 11, 2011 to launch a challenge to help break the Guinness World Records title for the most people doing jumping jacks in a 24-hour period. To break the record, more than 20,000 people from around the world must perform jumping jacks for one minute. REUTERS/Yuri Gripas
http://l3.yimg.com/bt/api/res/1.2/.B53vbi2byHHipEjRq6wwA--/YXBwaWQ9eW5ld3M7Zmk9aW5zZXQ7aD0zNjM7cT04NTt3PTUxMg--/U.S. first lady Michelle Obama greets children at an event on the South Lawn of the White House in Washington October 11, 2011 to launch a challenge to help break the Guinness World Records title for the most people doing jumping jacks in a 24-hour period. To break the record, more than 20,000 people from around the world must perform jumping jacks for one minute. REUTERS/Yuri Gripas