According to Blabbermouth.net, says that his life has changed for the better thanks to taekwondo.

"Taekwondo is a great discipline. For me, it was one of the things that changed my life," Mustaine said in a recent interview. "It (taekwondo) helped me to eliminate a bad lifestyle of drug and alcoholism. It helped me to believe inside of myself and find the strength inside of myself that I never knew that I possessed."

Mustaine made the remarks at the Grand InterContinental Hotel in Seoul on October 27, 2007, shortly after he received a certificate of appointment as the WTF's Goodwill Ambassador of the World in a ceremony.

"For me, it is a big responsibility and I am going to represent the WTF the best I can," Mustaine said of his appointment as the WTF's Goodwill Ambassador. "I am really excited to be the WTF Goodwill Ambassador."

Mustaine said that taekwondo is "the source of his confidence in his life." He is a 1st Dan black-belt holder.