His next challenge will be graduating from high school with a trim, healthy body.

Sebring said he was pleasantly surprised to find out his mom, Cathy, had nominated him for the 2010 Durham Fitness Challenge.

"I kind of joked with her that she should have just told me I was getting too fat," he said. "She usually gives me a head's up about those types of things."

Diagnosed with leukemia at 4 years old, and again at 8, after a four-month remission, Sebring said the doctors at UNC encouraged him to eat whatever he wanted while receiving chemotherapy and steroids.

Now, more than five years into his second remission, the Northern High School senior wants to trade those pounds for muscle.

He and two other challenge winners are getting help setting fitness goals and planning workouts and meals over the next three months.

The challenge is sponsored by the David Turner Lymphoma Foundation, named for a Durham resident who was diagnosed at 24 with Stage IV lymphoma, a cancer of the immune system. The Durham News will report on the participants' progress,

Sebring said it's hard to find exercise time. Besides school and homework, he works part time at the Treyburn Country Club golf course and plays bass guitar three days a week in the Ridgecrest Baptist Church band.

It's also his third year on the Northern golf team; he averages about 10 to 12 over par - pretty average, he said. But Sebring loves history, especially traveling around the East Coast with a state-based Revolutionary War regiment to re-create major battles.

"I call it camping for older folks," he said. "My cousins did it for a while, and I decided that I really wanted to do it."

Then there's college. Sebring wants to study pre-med at N.C. State University.

"It's going to be tough, but that's what I want to do," he said. "I think my experience will benefit me in that career. I might go into oncology or something like that."

Although he told his friends about the fitness challenge, they have their doubts, he said. His girlfriend is pretty supportive.

"She tells me she's happy how I look now," he said. "She's going to be dating a good-looking guy at the end of it, so I might as well tell her it's all for her."