At higher altitudes, the air is thinner, there is less available oxygen and it becomes more difficult to breathe. There are serious risks involved with high-altitude hiking, including altitude sickness, acute mountain syndrome and pulmonary edema, all of which can result in death. Before you go on a high-altitude hike, you need to train your body to work efficiently and effectively in environments with less oxygen.
Begin training at least two months in advance. This is especially important if you plan to hike at altitudes of more than 13,000 feet.
See a doctor for a medical checkup in the early stages of training to ensure that high-altitude hiking is a safe and recommended activity for your age and physical condition.
Hike as often as possible. The best thing you can do to prepare for higher-altitude hikes is to hike as often as possible and at increasingly higher altitudes, if possible. Start gradually, increasing the distance and altitude of your hikes with each week of training so that your body and lungs can become accustomed to functioning at increasing levels of altitude.
Participate in interval training. Interval training is a method of training the cardiovascular system by elevating the heart rate significantly and then allowing it to recover for a period before elevating it again. This prepares the cardiovascular system to deal with the stress of of limited oxygen levels at higher altitudes. Interval training could consist of running sprints, running hills, or using the interval setting on a treadmill or exercise bike. Choose one day a week for interval training and perform six repetitions of whatever exercise you have chosen. Each week, increase the intensity by running a faster sprint or a steeper hill. You also can train with a pack to add weight and simulate the weight of a pack that you might be carrying during the high-altitude hike.
Work on deep breathing and developing a breathing rhythm. Your ability to control and conserve your breath and expand your breathing capacity will come in handy when the oxygen supply is reduced. Develop a breathing/stepping rhythm that will prevent you from overexerting yourself at higher elevations, and practice deep breathing on training hikes. Whenever you begin to feel breathless, concentrate on taking deep breaths and smaller steps until a more normal breathing pattern returns.