Before joining UCLA, Giza worked on the Yosemite Search and Rescue team. In 2011, he traveled to Afghanistan as a civilian advisor to the U.S. Department of Defense. He co-chaired the American Academy of Neurology committee that developed an evidence-based practice guideline for the management of sports concussions from 2009-2013. He currently serves on advisory committees for traumatic brain injuries/concussion with the U.S. Centers for Disease Control, National Collegiate Athletic Association, Major League Soccer and U.S. Soccer Federation. He has been a clinical consultant for the National Football League, National Hockey League and Major League Soccer.