Nikos Sismanidis graduated from the Department of Economics at the University of Piraeus. He has many years of professional experience in banking, specialising in operational processes and information systems.

His martial arts background includes eight years of Wado Ryu and Shotokan Karate, two years of kickboxing, one year of Taekwondo and four years of Krav Maga. During his military service, he served as a medium tank commander and trained recruits in an armoured squadron.

In 2026, he successfully completed the Civilian Krav Maga Instructor Course with Krav Maga Guerrilla.