Maaser was born in Strausberg, Germany, to Silvia and Thomas Maaser, a former MiG-29 pilot. He started artistic gymnastics at the age of 3. Six years later he started martial arts and wheel gymnastics. Until today he is the most successful competitor in the history of the sport with 14 world champion titles, 2 world cup wins and more than 50 national titles as well as the title as the youngest ever world champion at age 14.