Unlike the whale or the polar bear, which have natural insulation in the form of layers of fat or fur, the human being is not an animal designed to survive easily in extreme conditions. Our bodies need protection from the elements. Humans rely on three sources of heat for warmth and protection: radiant heat from a heater, for example, warmth from our clothing, which protects our bodies from the cold, or heat generated from inside our bodies from the calories in the food we eat.


Sources of Fuel

When the human body is at rest, it has two principal sources of fuel — fat and carbohydrates. Historically, the diet in the far north has been very high in fat. The people of the north have been heavy consumers of marine mammals such as seal. But the nutrient needs of survival in the cold differ from the nutrient needs of physical performance in the cold. When the body becomes more active, it utilizes carbohydrates first because carbohydrates are the most rapidly converted energy source. Breaking down fat and converting it to energy takes longer. By focusing on carbohydrates as an energy source, endurance athletes are able to work harder, longer, and recover faster than if they relied more on fat.


Endurance Athletes

The IAP team members are considered endurance athletes. They need to be in excellent physical condition. They spend nine to ten hours each day either running or skiing alongside the sleds! This is done usually in conditions of extreme cold or strong winds. It is critical for the team to have the high calorie diet required in the cold conditions. A diet of up to 6,000 calories per day is not uncommon! But it is very important that the source of the calories be from carbohydrates more than fat.


Fat vs. Carbohydrates

When he led the historic expedition to the North Pole in 1986, Will Steger found that he craved fat. "It seems to help ward off the cold," he said. During the IAP 1993 training expedition, nutritionists from Shaklee Corporation, a company specializing in vitamins and nutritional supplements, conducted a study of the IAP team's diet. Team members responded daily to questions about the diet, fatigue, tension, vigor and confusion. Analysis found that their diet, high in fat, was negatively impacting the team's optimum performance. A diet with more emphasis on carbohydrate foods, with attention to the timing of food intake and use of a special nutrient drink designed to aid recovery, was developed for these IAP endurance athletes.


Additional Resources:

The American Running Fitness Association produces a monthly newsletter, Running and FitNews, which has articles about sports nutrition and treating injuries. For more information, you can contact them at 1-800-776- ARFA.


Runner's World magazine has a good nutrition column that runs in each monthly edition.