By Shaina Negron, CNN
(CNN) -- At age 16, Rob McCullough walked into an LA Boxing gym for the first time. The teen had left home, moving from one friend's couch to another, and now finally felt like he found a place where he belonged.
"I went to the gym and worked out, and worked out my stuff," he says. "That was kind of my safe haven."
After taking his first class and leaving with a compliment from the instructor, McCullough was hooked. "It built self-confidence," he recalls. "At the end of the day, I felt great about it."
Life was difficult at times for McCullough and his seven siblings who were raised by a single mother. Constantly relocating, he remembers how other kids were not always welcoming when the family moved to a new neighborhood. "I dealt with bullying growing up as a kid because I was always the new guy at the school," he says.
By the time he reached high school, a new challenge would shape his future.