Gabriel Martinez is a certified Mataas na Guro (Master Instructor) of the Pekiti-Tirsia Kali system and an Executive Director of the Pekiti-Tirsia Global Organization. He is the owner and director of the flagship Pekiti-Tirsia school in the United States, the San Antonio Pitbulls in San Antonio, Texas.

Guro Martinez began his study of the Filipino martial arts during his service in the U.S. Air Force while stationed in the Republic of the Philippines from 1987 to 1991. He received Instructor level certification in two Philippine martial arts before beginning his study of Pekiti-Tirsia in 1994. He is a private student of the Supreme Grandmaster Grand Tuhon Gaje and Maginoo Timothy D. Waid and continues to receive private instruction in the advanced systems of Pekiti-Tirsia. He is certified in the original systems of Doce Methodos and Contradas.

Guro Martinez is the recipient of the Bala-an Bukid Award for Exceptional Dedication and Loyalty to the Pekiti-Tirsia Kali system and is the first instructor of the Pekiti-Tirsia-Kali Pitbulls groups.

Guro Martinez is a certified AFAA Personal and Group Trainer and the creator of the Combat Aerobics program of the Pekiti-Tirsia system. Guro Martinez has been awarded special Instructor certifications in Dumog/Pangamut (DUMPAG), Combat Knife/Daga y Daga by Grand Tuhon Gaje, and is a Full Instructor in the Law Enforcement Defensive Tactics Safety System.

Guro Martinez served in the U.S. Air Force as an Emergency/ICU Medic and served as a member of a Tactical Field Hospital and the Neonatal Air Evacuation Team for the Pacific Air Command.