Oct. 10, 2011 -- C.J. Senter is a 10-year-old kid who has been on a fitness kick for half his life, and he is motivating other elementary school students to get fit.
This exercise guru from Locust Grove, Ga., has his own workout DVDs and is on a mission to get kids to build a physique like his. But few adults could ever hope for his six-pack abs.
C.J. started working out at age 5 for a pee-wee football tournament, and an exercise obsession was born. When he saw an infomercial for P90X, he begged his father to let him make a workout video of his own, marketed towards children.
"You can go outside and have fun, but some kids, they'll just go outside for like 10 minutes and come back in," C.J. said. "But if you just do a workout, your body will sweat more.
"Sweating, it lets, you know, you're losing weight," he continued. "You're really working."
According to the National Center for Health Statistics, nearly a third of all American children and adolescents are overweight or obese, putting them at risk for heart disease, Type II diabetes, asthma, and other ailments. C.J. might be the right role model to draw kids out of their sedentary lifestyles.
"I just want to get my message out to kids so they can get on their feet and have fun and learn new exercise," he said.
Heard Mixon Elementary in Covington, Ga., uses C.J.'s tapes with its 450 students as part of physical education class, and many of the children there seemed motivated.
"He inspired me because he was taking care of his body and exercising every day, and that inspired me that I need to exercise, too," said Andrew Mills, age 9.
Surprisingly, some of the kids were also body conscious.
"I got a lot stronger," said James Kirby, age 11. "Last few weeks I've lost about 10 pounds. ... I was a lot chubbier.
While any anti-obesity message might seem like a good thing, doctors who specialize in sports medicine say kids can dangerously overdo it.
"In my practice now, I've seen doubling of injuries to young kids, age 10 or 9 or 8, with overuse injuries because they're doing more now," said Dr. Robert Gotlin, director of Orthopedic and Sports Program at Beth Israel Medical Center in New York City.
Gotlin said that while tendonitis is the most prevalent ailment he has seen in active children, he has also seen young patients with bruising, as well as bone and ligament injuries.
"The problem with ligament injuries in children is the fact that ligaments in kids are very, very strong," he said. "So what happens is they don't tear but they pull the bone. And the ligament can actually pull the bone off the bone."
Having written about kids and fitness, Gotlin recommended children could work out up to an hour per day, with water breaks and mixing up their exercise -- such as aerobics, lifting weights. He offered a word of caution to children looking to get buff like C.J.
"What we have nowadays is children playing multiple sports or doing multiple activities," Gotlin said. "C.J., running track, playing football and working out ... that's overuse set-up, because he's doing three different things at one time."
For extreme mini-athletes, physical damage can be layered with emotional harm. Richard Sandrak, also known as "Little Hercules," was 8 years old when he became famous in the 1990s for his stunning physique. His appearance prompted claims that his parents were putting him on an excessive diet and exercise program and exploiting him. Sandrak's parents denied these claims.
C.J.'s parents, Adrienne and Carlos Senter, say they have not pushed their son into being super fit. If anything, the little fitness guru said he has been pushing them to shape up, encouraging them to exercise outside.
"The only thing I push C.J. into doing is going to school, making great grades and respecting others and treating them the way that he'd want to be treated," Carlos Senter said.
"It wasn't anything he set out to do on purpose," Adrienne Senter said. "Just with exercising and really just normal play for a child, he developed a physique."
His parents insist C.J. developed his body the old-fashioned way with calisthenics -- not weight lifting -- and they discourage other kids from pumping iron since it is widely believed to be hazardous to young bodies, but Gotlin disagreed.
"It's a fallacy and a myth that young children cannot lift weights. They can," Gotlin said. "Kids as young as 7 or 8 years old can lift weights very well. But the key is with supervision. They have to have an adult who's not just there in the room, but who's watching the child or coaching the child to make sure they don't get hurt."
The Senter family said they have sold or donated between 3,500 and 4,500 of C.J.'s workout DVDs, but said they aren't in it for the money.
"I coach football and I see a lot of kids coming back each year more and more out of shape," Carlos Senter said. "I figured that the best way to do anything with kids is with a kid, and he had the idea and we just moved forward with it."
C.J. said he dreams of one day playing in the NFL, but if that doesn't work out for him, he already has built an impressive body of work.