Jeremy “Lionheart” Flauding attended grade school at Washington State, where he wrestled in junior high and high school. While in High School, Jeremy started taking Shotokan Karate. A year after graduating, Jeremy moved to California in 1996 and quickly found a home training Muay Thai at Concord Kickboxing Club under Daniel "Doc" Doctor.

In 1999, Jeremy would continue his Muay Thai training at what is now known as Combat Fitness under George "TNT" Tsutsui, one of the prodigy fighters from the world-famous Fairtex School of Muay Thai. Jeremy later transitioned from fighter to instructor, teaching Muay Thai for 11 years at a local martial arts school.

Undersized as a child, Jeremy began wrestling and weightlifting in the 8th grade. Growing up with movies like Kickboxer, Blood Sport, and Enter the Dragon, Jeremy had always been enamored with martial arts, but coming from a small town, there was little opportunity for exposure. Jeremy was exposed to the first Ultimate Fighting Championship through his first martial arts instructor, dramatically changing his view on martial arts.

Moving to California at 19, Jeremy was excited to find an abundance of martial arts available and immediately began training and competing. While fighting multiple times on the same day at a smoker held by the late Alex Gong at Fairtex of San Francisco, Jeremy was nicknamed "Lionheart" by Bunkerd Fairtex. Jeremy fought in various martial events in the late 90s and early 2000s, including Muay Thai, Sanda, MMA, and Brazilian Jiu-Jitsu.

Jeremy met Professor Crosley Gracie at Combat Fitness in Concord, CA, while Crosley was training for a fight in Pride Fighting Championships in Japan in the mid-2000s. Jeremy has over 25 years of experience in Muay Thai as a fighter, coach, and instructor. Jeremy has also obtained a purple belt in Brazilian Jiu-Jitsu and works as an Animal Control Officer for Contra Costa Animal Services.