Presidential Fitness Challenge
U.S. Air Force Staff Sgt. LaQuita Pierce, 373rd Support Squadron, walks on a treadmill Sept. 9, 2010, at a Misawa Air Base, Japan, fitness center. Sergeant Pierce regularly walks to stay in shape as part of her routine exercise program. Walking is one of more than 100 activities listed on the President’s Challenge Web site. (U.S. Air Force photo by 1st Lt. Cammie Quinn/Released)