Pittsburgh Diabetic Takes Trek to South Pole in Stride

To Will Cross, trekking to the South Pole while hauling a heavy sled laden with supplies was good exercise.

“You couldn’t make this trip if you were a slug,” Cross said. “I know my fitness is improved. You can feel your muscles working, and you can feel your system requiring more calories.”

Cross spoke by satellite phone from his tent near the U.S. Amundsen-Scott South Pole Station, a research facility about 1,150 feet from the pole. The 35-year-old Pittsburgh schoolteacher is the first person with type 1 diabetes to trek to the bottom of the world. He reached it Jan. 17.

Like many an adventurer, one of Cross’ goals in the 730-mile, 61-day journey was to show that it could be done. “I think embarrassingly little is known about diabetes and so therefore our initial tendency is to say it can’t be done,” he said.

Although Cross had the advantage of Antarctic summer -- the temperature was a balmy near-freezing the day he arrived -- the trek was tough sledding. His traveling gear weighed about 150 pounds when fully loaded, and he hauled it 10 to 12 hours a day, taking a day off once every two weeks. He resupplied twice.

Explorers Robert Scott and Ernest Shackleton traveled on foot early in the 20th century, and Cross pointed out that he traveled the same way.

“Manhauling in the traditional style,” he said by way of description. “You wear a harness that goes around the waist and around your shoulders. Your Achilles tendons and your calves hurt [and] the balls of your feet, from digging in at the skis. Your shoulders are painful because the straps just pull away at you. And you do that day in and day out.”

It’s no easier today than it was in the days of Scott and Shackleton, “except that perhaps our gear is better and we know a lot more about food,” Cross said.

Food was of special concern for Cross. To keep his energy up, he consumed more than 6,000 calories a day on a special high-fat diet developed at the University of Pittsburgh. But he had to balance the intake carefully with injections of insulin needed to carry it to his cells. As a type 1 diabetic, his body makes no insulin.

Energy intake, insulin and hard work were “the daily juggle,” and along with blood testing, balancing those factors kept him healthy for the two months that he spent on the ice, Cross said.

His blood sugar was 200 milligrams per deciliter of blood in the morning -- above what doctors like, but as he drew down his energy stores, the levels fell into the normal range.

And according to a monitor he wore, his heart rate while pulling the sled fell from 138 beats per minute early in the trek to 112 near the end, Cross said. The drop is a sign that his body had adapted to the strain and was working more efficiently, putting less strain on his heart.

Cross did not travel alone. Companion Jerry Petersen stayed with him from the start in the Patriot Hills on the east side of Antarctica. Petersen does not have diabetes, but his father died of complications associated with diabetes.

For the last 100 miles, they were joined by Cross’ father, Mike, also a type 1 diabetic, and physiologist Bret Goodpaster of the University of Pittsburgh, who studies the exercise response of people with diabetes.

Besides being an adventure and a research expedition, the trek was a fund-raiser for the Juvenile Diabetes Research Foundation International. Juvenile diabetes is an older name for type 1 diabetes, which is more commonly first diagnosed in children than type 2 diabetes. Type 2, however, is the most common form, accounting for about 90% of all cases. In type 2 diabetes, the body does not make enough insulin or cells ignore the insulin.

“He is a demonstration of what the upper limit is,” said Dr. Richard Furlanetto of the University of Rochester, scientific director of the Juvenile Diabetes group. “You can do anything with type 1 diabetes as long as you know yourself and understand your diabetes.”

“This is obviously an extraordinary feat, and Will is a great example,” said Dr. Francine Kaufman of Childrens Hospital Los Angeles, president of the American Diabetes Assn. But what he did differs only in amount, not in kind, from what ordinary people with diabetes should do, she said.

Doctors encourage people with diabetes to exercise. Physical activity helps remove sugar from the blood and strengthens the cardiovascular system. Cardiovascular disease is the leading killer of people with diabetes.

But, like Cross, people with diabetes who exercise should work with their medical team, Kaufman said. An exercise prescription has to account for calories eaten in food, calories burned in exercise and variations of any insulin doses needed to balance the two sides, she said.