With three older brothers, Lauren Fisher quickly learned how to play with the boys.

“She would just never back down,” says Fisher’s mom, Linda.

At 12 years old, Fisher started training at CrossFit 209 Sport in Stockton, Calif. As with other athletes who start CrossFit early in life, Fisher improved quickly and reached a high level of fitness at a young age. Last year, at 17, she competed at the 2012 NorCal Regional and finished 12th. This year, she went to the CrossFit Games as a member of the CrossFit Invictus team, which finished seventh.

“One of the things that we did right from the get-go is we train at 7 a.m. on Saturdays, knowing that last year she was a freshman in college. I was interested to see how that would play out,” says C.J. Martin, owner of CrossFit Invictus. “She never missed a training session.”

Fisher’s dedication and attitude have garnered admiration even from more experienced CrossFit competitors and coaches.

Miranda Oldroyd is a member of CrossFit’s Level 1 Seminar Staff, as well as a coach at NorCal CrossFit alongside Fisher’s brother Garret, who finished fifth at this year’s Games. Oldroyd says she’s “super jealous” of the 19-year-old.

“She has realized so early on in her life not to care what anybody else thinks,” Oldroyd explains. “She has learned so early in her life what she can get just by working hard and having goals and what it means to work hard. They’re so much more mature … when they find CrossFit earlier in their life.”

Video by Jay Vera.