Nutrition

Nutrition and hydration are extremely important aspects as much during the training before the expedition, as during the real development of the expedition. Our body uses the energy from the food to keep the basal metabolism stable and to cover the requirements produced when voluntary physical exercise is performed.

Nutritious needs balance during the ascent to Aconcagua

Representation of the amount of calories which should contribute by the different energetic nutrients during an expedition to Aconcagua:
-Proteins: 10 / 15%, where 1gr. of proteinsprovides 4 calories.
-Fats: 25 / 30%, where 1gr. of fat provides 9 calories
-Carbohydrates: 50 / 60%, where 1 gr. of carbohydrates provides 4 calories.

The factors which determine energeticconsumption during physical exercise are: Intensity, Duration and involved muscular Groups. It resultsinteresting to analyze the characteristics to ascend the Aconcagua from this point of view, to develop an adequate nutrition plan. The intensity is high due mainly to the physical exercise in altitude.

This intensity is situated in the aerobic threshold, that is to say, in the limit of this capacity (also named aerobic power). Regarding the duration, it is long, since we usually have9 or 12hr-activity days.Concerning the involved muscular groups, we have mostly the thighs (which are our body´s biggest muscles), the ones implied in climbing traction. Also the thoracic cavity muscles, owing to the hyperventilation, typical of physical exercise in height.

With this we shall conclude that an ascent to Aconcagua is considered a very high energetic requirement activity with agreat physical wear, therefore a meticulous preparation of the diet plays a very important role, paying special attention to the altitude trekking days (over 4500masl), which are the more demanding ones, causing low oxygen saturation levels, and it often creates a bigger sensitivity on the digestive system.

For example, on the stretch Plaza de Mulas / Plaza Canadá, a climber might burn up to nearly 4450 calories on the entire day. Around 10000 calories could be burnt on the summit attemptday.

Food Selection

The basis of mountaineers strengths arein a big part a good nutrition. The recommended calorie source is shared among glycides (sugars), lipids (vegetable and animal origin) and proteins. Food must be easy to digest, tasteful, easy to transport, not too heavy or voluminous and diverse. Always trying to eat quietly, not too much, just enough, chewing well.

For instance, spaghettis or other kind of dried pasta are simple to cook and it is possible to combine them with cream or olive oil, contributing carbohydrates and lipids.

A piece of cheese and hamadd proteins and salts. Crackers, spreadable cheese, olives and some peanuts are always welcome as appetizers. Dehydrated smashed potatoes or polenta are excellent options for the 6000masl, since they offer abundant carbohydrates easy to assimilate. Individual quick cooking soups or just bouillon cubes well diluted must be present during the itinerary. Breakfasts will be included between the important meals, plenty of hydration accompanied by bread and butter, marmalade or honey, cookies, cereals with milk and a portion of pudding. A cookie or an energy bar forthe march and a sandwich with dehydrated fruits for rest.

In short, each person will prepare a menu with provisions of its own preference. The aim must be to recover most of the burnt calories, with a balanced, nutritive and tastefuldiet, to stimulate the appetite, which decreases by the effects of hypoxia.

Hydration

In mountaineering hydration is just as important asfood or even more, since the lost of liquids is really relevant. This gets worse as we ascend and gain altitude, because the lack of oxygen saturation in blood causesa compensatory hyperventilation (hypoxia), losing a lot of liquid in the form of water vapor by breathing. The specially dry air and perspiration are other ways to lose fluids.
The rhythm of fluids lost, varies from one person to another.

Liquids lost are produced by breathing and perspiration, as we already said, but also by urine and diarrhea. We are not always aware of the amount of liquid our body is losing. Certain drugs such as azetosolamide (Diamox) could induce dehydration due to its diuretic power.
Keeping a proper hydration is elemental to reduce the risk of heat, cold (including freezing) and altitude disorders.
Not replacing the liquid lost, leads to dehydration, affecting athleticperformance markedly. If dehydration goes forward it can steer a state of shock.

Liquids replacement

The conventional way to replace liquid is to drink water, but in the mountain, especially in high camps (over 4500masl), this vital element is hard to obtain. In fact, in some stretches of the ascent it is only possible to get water bymelting the snow or ice from a snowfield or penitent camp. The problem is that this water practically lacks the minerals which placate our thirst and replace the fundamental minerals, particularly sodium.
In these cases it is important to enrich the water by adding some mineralsto accomplish the hydration function.It is possible to carry this out by different ways, either preparing infusions as tea, soup or juices.
During an expedition to Aconcagua it is required to drink around 5 liters of liquid per day to procure rehydration and to compensate the adaptation to height.The variation of liquids and flavors is advisable, since this helps the body to receive them more at ease.