When American swimmer Gary Hall Jr. springs off the platform at the 2000 Olympics in Sydney, Australia, his endocrinologist, Anne Peters, M.D., USC professor of medicine, holds her breath.

And the wondering begins: Will Hall's body be able to muster up enough energy to thrust him to a gold medal, and remain healthy?

It's a reasonable rumination for a physician caring for a patient with type I diabetes, a diagnosis disclosed to Hall after a period of lethargy and blurred vision in March 1999. It particularly makes sense for Peters, who personally enabled Hall to get back in the pool with a fighting zeal.

"When he got the diagnosis of diabetes, his dad said, 'Gary's really depressed. You've got to tell him he can go back to swimming,'" Peters recalls. Back then, Peters was a prominent diabetes specialist at UCLA, and Hall approached her for help. Other endocrinologists had said that a return to competitive swimming was too risky for the 25-year-old Arizona native, who had won two gold medals and two silvers at the Atlanta Olympics.

But Peters met with him, and said: "I don't see why not." That was all Hall needed to hear to get his swimming career kicking again.

"He needed a hero, someone to say 'you can do it,'" Peters remembers. "I took a day off, flew up to Berkeley, watched him train, and checked his sugar. I decided he could do this."

Since then, Peters has gone with him to major swim meets in preparation for the Olympics.

"He trusts me," Peters says. "He knows he has me there; my entire job is to help him be healthy—the swimming is up to him."

Peters helps keep his sugar levels balanced, a tough proposition considering Hall swims so hard that his blood glucose levels may drop dramatically during a race. "I'm always afraid that the teeny difference between winning and losing—that tiny split-second—will be because I didn't help him enough," Peters says. "What if he's one glucose molecule away from winning?"

Diabetes is a chronic disease with no cure as of yet. Doctors know of several forms of the disease, including type 1, or insulin-dependent diabetes mellitus; type 2, or non-insulin-dependent diabetes mellitus; and gestational diabetes.

Normally, certain cells in the pancreas called beta cells produce the hormone known as insulin. The body uses insulin to help get glucose into cells, where it can be used for energy. But sometimes problems arise in the process.

In the case of type 1 diabetes, beta cells in the pancreas often are damaged or no longer existent, so the body does not get the insulin it needs. Those with type 1 diabetes need insulin injections, and exercise and dietary changes also help. They also need to check their blood sugar levels regularly to make sure they stay balanced.

"It takes a lot of work to help an athlete like this," Peters admits. "But with Gary, his intensity is so much greater than a typical person. He's inspiring."

Peters may identify somewhat with Hall, a free spirit who tackled his diabetes as a challenge to be met. (Like Hall, "I march to my own drummer, and it seems to work," she says.) She got him involved in diabetes advocacy, and now Hall has transformed himself from an idiosyncratic, quiet athlete into an outspoken role model for people with diabetes. He receives hundreds of letters from diabetic children and teens, Peters says.

"What hero can you think of for people with diabetes?" Peters asks. "Gary is that hero."