“I started a lot of fights and used to mess up the classroom,” said Levi.
The 14-year-old has ADHD, and now boxes in a bid to channel his excess energy and improve his life skills.
Fellow boxer Jamie, 11, was excluded from school when he was just nine.
“The boxing helps me get my anger out and it helps me control it,” he explained.
Coach Nathan Powell, at Colcot Amateur Boxing Club in Barry, said: “At the start of the sessions, team activities always end in arguments and confrontation.
“But with work and drills, their confidence grows and they become a member of a team.”