Senior Airman Adrian Castillo, 2nd Security Forces Squadron, exercises his upper body at the fitness center on Barksdale Air Force Base, La., April 11. Physical fitness plays a large part in a service member's career, especially in a highly physical career field such as security forces. Castillo works out at least once a day to maintain fitness standards. Many Airmen utilize the fitness center to take advantage of the amenities such as weights, basketball courts and outdoor and indoor tracks (U.S. Air Force photo/Airman 1st Class Andrew Moua)(RELEASED)