(Credit: Official White House photo by Chuck Kennedy)

The normally dignified Blue Room at the White House became a late-night show comedy set last month when first lady Michelle Obama engaged in a friendly game of tug of war with host Jimmy Fallon, according to a photo released by the White House  today.

The scene, part of a taping for Fallon's show, is meant to promote Mrs. Obama's commitment to physical activity - and good humor - on the second anniversary of her "Let's Move!" initiative aimed at fighting childhood obesity.

The first lady embarks Thursday on a three-day national tour to celebrate the milestone with stops in Iowa, Arkansas, Texas and Florida.