Complex sentence: Mitrione also trained in Shotokan Karate, Kickboxing, among other combat sports as a teenager, even competing in Toughman Contests while he was still in high school and finished second in a tournament in his hometown of Springfield, during his sophomore year of college.
Split into simpler sentences: Mitrione also trained in Shotokan Karate, Kickboxing, and other combat sports as a teenager. Mitrione even competed in Toughman Contests while he was still in high school, and finished second in a tournament in his hometown of Springfield, during his sophomore year of college.