As a young adult, Vandenberg competed in many martial arts competitions, winning most of them, and left school at age sixteen to enroll in a Kunto training course in Okinawa, Japan.
Vandenberg volunteered for a post in Germany as it offered a shorter service of eight months (as opposed to a year).
Vandenberg won the competition with only two months of training but was hit by a car and broke his leg.
[2] Unable to fight in further events, Vandenberg left Belgium to join the French Foreign Legion.
He spent five years in countries such as Chad, Nigeria, and the Central African Republic, fighting to control rebellions.