One girl, who did not want to give her name and who goes to the boxing club, said she was once threatened and told she was going to be stabbed and, when she told her school, they did not allow her to go in for a week.
She said she enjoyed going to the gym as she “always has someone to talk to”.
“Even if I come in sad, I’ll always leave happy,” she added.
The summer holiday sessions have been funded by the West Midlands Violence Reduction Partnership as part of its My Tomorrow campaign to improve young people’s lives.
More sessions will be held in October, organisers said.