Marquardt was born in Lander, Wyoming and was raised in Denver, Colorado. His late father was a Lutheran pastor and also worked in construction. Marquardt's father was also a former Marine who fought in the Vietnam War, Marquardt's mother was a nurse and a manager at an attorney's office, and Marquardt is one of five siblings. Because of his father's work he and his family moved around frequently to places including Chicago, Illinois, and Indiana. His parents divorced when he was eight years old, and the young Marquardt moved to Colorado. When he was 15 years old, he began studying the disciplines of Brazilian jiu-jitsu, kickboxing, and kenpo. He was very active in sports, including basketball and soccer, at Wheat Ridge High School and also began taking freestyle wrestling and BJJ lessons when he was 18 years old under the instruction of Ricardo Murgel.