To trek in the Himalayas your cardiovascular endurance is the most imparted and crucial thing.
Cardiovascular endurance is the ability of heart, lungs and blood vessels to deliver oxygen to your body cells. The more efficiently Your body sends oxygen to its tissues the lower your breathing rate is.
Why is it so important?
More than 140 millions people worldwide are living at an elevation higher than 2500 meters (8200 feet), making a more effective flow of oxygen in their body, while their breathing is essentially at the same rate.
Our bodies are not meant to handle incredibly frigid temperatures, the high winds, or the lack of oxygen that are common in high altitude places Himalayas and thus we are forced to come properly prepared mentally and physically.
As you climb high, due to decrease in air pressure the temperature decreases with height along with oxygen levels. At high altitudes human body is deprived of oxygen.
The main (obstacles) of high altitude mountaineering is low level of oxygen because of thin layer of atmosphere at higher levels above sea level, which in turn increases risk of sun burn too.
If we consider Everest (8848M), there is 1/3rd of oxygen available as compared to sea level. It is important to realize that the reduced pressure does not allow as much air into your lungs, which can therefore not absorb as much oxygen as your body needs. The way the human body reacts to this problem is what causes AMS (Acute Mountain Sickness) , HACE (High Altitude Cerebral Edema) and HAPE (High Altitude Pulmonary Edema).
Acute Mountain Sickness
When you seem to have attained an altitude of about 2500M (8200 Feet), the body starts reacting and responds to the effect of high altitude. The body begins to adjust to the whether conditions by increasing the amount of blood flow into brain. However if the blood flow reaching to the brain excesses then the process begins to swell the brain, and if this process persists it can result into multiple sumptoms,
- Shortness of breath
- Nausea or Vomiting
High Altitude Cerebral Edema
If the brain swelling problem increases more, there are chances that it will get into extremely dangerous condition, known as High Altitude Cerebral Edema. It usually affects when a climber goes above 3050m (10,000ft). Symptoms of HACE includes,
- Profoundly inhibited mental function
- Loss of muscle coordination
- Impaired speech
- Severe headache
- Nausea or vomiting
High Altitude Pulmonary Edema (HAPE)
This condition is one of the biggest threat that can happen to you on mountain. In process of gaining more oxygen, the body sends more blood towards the lungs, which also starts building fluid as like brain. This develops Flu like symptoms which can become severe to cause death. Every climber should be careful above 3050M(10,000ft).
- Extreme difficulty breathing
- Very rapid breating rate
- Lack of motivation
- Pale complexion
- Constant coughing
- Gurgling sounds coming from chest
How can one acclimatize in these conditions?
It is extremely difficult for a human body to rapidly adapt to fast changing altitude pressure. When climbing, it is advisable to adapt "climb high sleep low" strategy. During the expedition or alpine climbing, mountaineers will often climb as high as they safely can during the day, but return to a much lower elevation to sleep.
Try and increase the sleeping elevation by only 350M (1150 Feet)per day, greatly reduces the chances of getting one of the potentially deadly altitude related condition. (AMS, HACE, HAPE)