First Lady Michelle O. Faces Off with Jimmy Fallon.

On Tuesday night's "Late Night with Jimmy Fallon," the First Lady invited Fallon to the White House for a little friendly physical competition. Though the contest got rough at times, it was all for a good cause: to promote Mrs. Obama's "Let's Move" initiative, which encourages healthy eating and physical fitness for America's kids.       Fallon opened the segment by explaining, "Here at 'Late Night' we make exercise and staying healthy a top priority." He continued, "we're also big fans of the First Lady's 'Let's Move' initiative, which encourages kids to get active." The NBC host said that he "connected" with a clip of Obama saying that she is "pretty much willing to make a complete fool out of myself to get our kids moving." Fallon then said, "I make a fool of myself every night, so I decided to go down there and help the First Lady out."