The exposure to cold, mixed with the physical exertion of backcountry travel, depletes the body of energy and water quickly. Without rehydrating and replacing energy, the human body lacks the ability to transport oxygen and nutrients to the muscles, through the blood. The reason people become tired right after eating, is because blood is also used in the intestines to help digestion. By eating small amounts throughout the trip and continuously drinking fluids, muscles can continue steadily without complete burnout. Besides, trying to stuff yourself after a long hard day may produce indigestion and fatigue that lasts for several hours.

Bring foods that you enjoy, because extended hiking at altitude can reduce the appetite. Taking a variety of food will help the body utilize different nutrients, increasing energy. Many athletes look down on sugar because it gives a quick energy boost, as opposed to complex carbohydrates which provide long lasting energy. Some candy is fine, but be sure to mix it with more nutritious foods. Light weight items, that will not turn to pulp, are the best. A smashed banana in the pack is not quickly forgotten.

Although many people prefer a hot meal, it is better to have items that don't require cooking during the day. Even at night there are times when it's too late, too windy, or you're too tired to cook. Besides you still have to melt and boil snow, for hot drinks, as well as for water the next day. Dried fruits, nuts, cheese, beef jerky, canned meats, sausage, crackers, bagels, chocolate, candy and energy bars are among favorites. Dehydrated pastas, soups, tea, cocoa and packets of oatmeal are also easy to prepare and clean up. My favorite items are oranges, fruit bars, hot pepper cheese and Stouffers boil in a bag meals. (These items are fairly heavy but good for short trips.) Bring enough stove fuel for increased cooking times at altitude and pack extra food in case of an emergency.

If you are thirsty, you are already dehydrated. The recommendation for the average person to replenish water, after intense activity is two quarts. For hot environments, four quarts. Salt replenishment is also important. Tablets of salt or powdered drink mixes can be used for sodium replacement. Carry a water bottle, canteen or camel back and continuously drink water all day to keep the system running smoothly. It's just like a car needing the right amount of oil. If there is not a lot of fluid in the stomach, digestion of food is much faster. So, drinking a little at a time all day, instead of just during a meal is more efficient.

When preparing to refill water bottles by melting snow, it is faster to start with some water each time and use dense snow because it has a higher water content. If using water out of the creek, or anywhere Ghiardia may be found from human or animal waste, it is essential to use purification tablets or filters. Boiling the water for ten minutes, or more at high altitude will also kill the bacteria, but other methods are usually more convenient. Once the bottles are filled for the next day, put it beside your body that night so it will not freeze.

For optimal performance eat and drink small quantities throughout the entire day. Carry a variety of foods you really like, that are easy to prepare and high in long lasting energy. Then think of rehydration as the source of blood, supplying the muscles with much needed fuel to go bigger, faster, and higher.