He still recalls the response from doctors and would-be corporate sponsors: "They said it couldn't be done by someone with diabetes, that it's a 'suicide mission.' "
They were wrong.
Cross, a 35-year-old Pittsburgh school administrator who has Type 1 diabetes, just returned from the journey that would test the mettle of most anyone, diabetic or not.
Temperatures plunged as low as 30 degrees below zero Fahrenheit during the journey from the Antarctic coast to the South Pole. For two months, he spent days traveling up to 12 hours on skis while pulling a supply-laden sled. Much of the trip was against the wind and uphill, and nights were spent sleeping in a tent, where relative warmth meant temperatures just above freezing.
The "NovoLog Ultimate Walk" -- named for the sponsor, which makes a pen-like insulin injection system Cross used -- raised about $750,000 for juvenile diabetes research in contributions from individuals, private foundations and corporations.
Cross says the mission accomplished two key goals: To dispel myths about what diabetics can and can't do and convince them exercise is healthy with the right diet and proper insulin monitoring.
"Children and parents typically face a barrage of misunderstandings about diabetes, and most keep a guarded approach to activity," says Cross, a father of four who heads a program for at-risk students at a Pittsburgh high school.
"I think there are two ways you could look at this trip. One way is, 'I could never do that.' The other way for a diabetic to look at it is, 'My goodness, if that can be done, imagine what I could do on the soccer team.'"
Jerry Petersen, a 36-year-old who does not have diabetes but whose father died of diabetes-related complications, made the trek with Cross. Two others joined them for the last 120 miles of the journey: Cross' father, 60-year-old Michael Cross, who also has Type 1 diabetes, and Bret Goodpaster, a University of Pittsburgh researcher who was studying how well someone with diabetes would perform under extreme conditions while subsisting on a high-fat, high-calorie diet.
Pitt researchers developed the diet, containing 7,000 calories a day and featuring foods including cookies, candy bars, Slim Jims, Pringles, nuts, sticks of butter in coffee, olive oil in cereal, and nuts.
Not exactly the expected food choices for a diabetic. However, Goodpaster says the carefully selected diet supplied Cross with the calories needed for such a physically taxing expedition and that such strenuous exercise burns the calories quickly.
Cross, who, as a Type 1 diabetic, produces no insulin, closely monitored his blood sugar using a device to prick his finger to ensure he wasn't getting too much or too little insulin, says Goodpaster, an assistant professor of medicine in Pitt's division of endocrinology and metabolism. Exercise and insulin both cause the body to use more blood sugar, Goodpaster explains, and exercise improves the body's ability to use insulin efficiently.
He notes that heart disease is the No. 1 killer of diabetics, and stresses the importance of exercise to improve cardiovascular health. During the two-month journey, Cross' heart rate while pulling the sled decreased significantly, and that's a classic sign of improved fitness, showing less strain on the heart, Goodpaster says.
Both Cross and Peterson returned from the trip in better shape than when they left, and except for the frostbite Cross' father suffered, nobody had any ailments. Cross, who had gained 30 pounds when he bulked up to prepare for the expedition, came back 30 pounds lighter, weighing 170.
"One of the things we sought to do was to show kids with diabetes and their families not to be afraid of exercise," Goodpaster says. "You can exercise. In fact, it's healthy to do that. You just have to know that exercise will affect how much insulin the diabetics should give themselves."
Goodpaster, who followed most of the journey's progress from afar, got a surprise when he actually headed out himself. "I thought how hard can skiing at a slow pace be?" says Goodpaster, a competitive cyclist. "Let me tell you when I got out there, I found out how hard it was. It really increased my respect for [Cross and Peterson]."
Cross and his dad, however, may have had more realistic expectations. Cross has scaled Mount McKinley and completed a two-week North Pole expedition, and father and son have journeyed together on treks across the Sahara and the Thar Desert in India.
At the bottom of the world, they saw what most will never behold: Antarctic terrain that, by turns, resembled the salt flats of Utah, a choppy ocean, even another planet.
"Seeing the moon from Antarctica was the inverse image of the famous earth-rising shot taken early in the Apollo missions -- and evoked wonder," Cross says. "I think in a place like that my answer to prayer and faith is that God is certainly there, all around."
For more on the journey, visit the NovoLog Ultimate Walk. To learn more about juvenile diabetes, check the Juvenile Diabetes Research Foundation International.