An endurance diet can provide the energy and nutrients necessary for peak performance in the Arctic. That's because fat is a concentrated energy source that supplies nine calories per gram. Carbohydrates and protein , on the other hand, provide four calories per gram each. But consuming fat does not allow the body quick access to calories. Current thinking favors a diet low in fat and high in carbohydrates.
Carbohydrates supply large amounts of the sugar glucose.
They can be stored in muscles and in the liver as a compound called glycogen , which quickly converts to sugar when needed, providing ready energy for exerting muscles. They'll eat rice, pasta, and many grains and supplement those foods with products specifically designed for muscle recovery after strenuous exercise. On days of rest, the explorers will stock up on carbohydrates to replenish their muscle reserves of glycogen. A carbohydrate-rich diet does have drawbacks. Because it takes about twice the amount of carbohydrates to provide the same number of calories found in fat, the sleds must carry heavier loads.