Chuck Norris started learning martial arts while working as a police officer for the U.S. Air Force in South Korea.

Carlos Ray Norris joined the Air Force in 1958. While serving in South Korea, his fellow airmen gave him the nickname Chuck. He began training in Tang Soo Do, which is a Korean martial art. This style combines movements from karate and older Chinese fighting methods.Norris practiced for several hours every day after his work shifts ended. He focused on forms called hyung and sparring called dae ryun. These exercises build muscle memory and help the brain react faster during a fight. By the time he left the military in 1962, he had earned his first black belt.The military uses a decision-making process called the OODA loop. This stands for Observe, Orient, Decide, and Act. Martial arts training uses similar steps to help people stay calm and focused under pressure. Studies show that soldiers who practice martial arts have better situational awareness.Norris used his military discipline to open his first karate school in Torrance, California. He later created his own martial arts style called Chun Kuk Do. He served in the military for four years and received the National Defense Service Medal for his time on active duty.