Have you ever dreamt of conquering the high-altitude Himalayan trails and experiencing the majesty of the snow-clad mountains up close? Trekking such trails is an exhilarating experience with a lot to offer.
You will definitely have the experience of a lifetime as you will be treated to stunning views, a sense of adventure, as well as a newfound connection with nature.
However, whether you are a beginner or an experienced trekker, understanding the importance of acclimatization is an important part of having a safe and enjoyable experience.
Proper acclimatization can mean the difference between a safe and smooth trek and a chaotic trek with a possible dangerous encounter with health hazards caused due to high altitude.
Therefore, in this blog, we have presented the ultimate guide to acclimatization for high altitude treks. Continue reading and be prepared to get valuable insights on acclimatization.
What is Acclimatization?
If you are someone who has researched regarding any trekking route, especially a high-altitude trail, you might have come across the term acclimatization quite a lot of times. But what really is acclimatization and why is it so important? Let’s find out.
So, first of all we need to know clearly what exactly acclimatization is. To put it simply, acclimatization is the process in which your body adapts to the extreme conditions that the high-altitude regions present.
While on a high-altitude trek, the level of oxygen decreases as you reach the higher altitude region, especially beyond 2,500 meters (8,202 ft) and above. It is because the air thins out and this leaves a limited amount of oxygen for your body to use.
As these conditions are new for your body, it takes time to adjust to this and the process that it undergoes to adapt is called acclimatization. If you trek without allowing your body to acclimatize well, you might experience several health hazards related to altitude.
Why is Acclimatization Needed?
Acclimatization is not just a trend or one of the things that you should try during high altitude adventures. It is a necessity which must be followed as lack of acclimatization can lead to several health hazards.
The lower level of oxygen at high altitude can impact your respiratory system as well as circulatory system. Your body will struggle to both take in oxygen as well as to circulate it in your body.
Therefore, both your respiratory system and your circulatory system will be working overtime in such a region. As your body has to work harder for oxygen, it might leave you with breathlessness, fatigue, and other issues.
Acute mountain sickness is one of the most common altitude related issues that you can have if you don’t acclimatize well. You will see symptoms like nausea, dizziness, loss of appetite, loss of sleep, and more.
At times, it can even turn into more deadly problems like High Altitude Pulmonary Edema (HAPE), where fluid builds up in the lungs, or High-Altitude Cerebral Edema (HACE), where fluid builds up in the person’s brain. These conditions can even be life threatening.
Sometimes trekkers might even get hypoxia where a part of the body might be deprived of adequate oxygen supply and lose its functioning. Therefore, to prevent altitude sickness, acclimatization is of utmost importance.
How Does Acclimatization Work?
When adapting to the challenging conditions of high-altitude trekking trails, there are many physiological changes that your body might go through. Some of these changes might be immediate and some might take time to kick in.
| Altitude (feet) | Altitude (meters) | Oxygen Level | Reference Place |
| 1,000 | 304 | 20.1% | Dharan |
| 2,000 | 609 | 19.4% | Besi Sahar |
| 3,000 | 914 | 18.6% | Pokhara |
| 4,000 | 1,219 | 17.9% | Kathmandu |
| 5,000 | 1,524 | 17.3% | Jhinu |
| 6,000 | 1,828 | 16.6% | Danaque |
| 7,000 | 2,133 | 16% | Lalitpur |
| 8,000 | 2,438 | 15.4% | Chandragiri |
| 9,000 | 2,743 | 14.8% | Lukla |
| 10,000 | 3,048 | 14.3% | Upper Pisang |
| 11,000 | 3,352 | 13.7% | Namche Bazar |
| 12,000 | 3,657 | 13.2% | Muktinath Temple |
| 13,000 | 3,962 | 12.7% | Annapurna Base Camp |
| 14,000 | 4,267 | 12.3% | Thorong Phedi |
| 15,000 | 4,572 | 11.8% | Gokyo |
| 16,000 | 4,876 | 11.4% | Tilicho Lake |
| 17,000 | 5,181 | 11% | Everest Base Camp |
| 18,000 | 5,486 | 10.5% | Kalapathhar |
The most common way that acclimatization works is by inducing hyperventilation where your breathing rate gets increased along with your heartbeat. This is because of the said overtime work by your body.This compensates for the lack of oxygen and allows more oxygen to enter your blood stream. This is one of the immediate changes and starts within hours of reaching high altitude areas.
Another physiological process that takes place over a period of 5 to 6 days is that your body starts producing more red blood cells which helps in efficient transportation of oxygen within your body.
If you stay in the high-altitude region for a longer duration like a month, your body will be completely acclimatized, and your muscles and tissues will adapt to utilize oxygen more effectively which can make physical activity much easier.
The basic process of acclimatization sets in within 1 to 3 days of reaching the high-altitude region, usually beyond 2500 meters (8,202 ft) to 4,000 meters (13,123 ft). However, for an altitude beyond that, it can take a longer duration.
Therefore, it is important that you set your itinerary in a way that you ascend limited amount every day and allow your body ample time to begin the process of acclimatization.
Tips for Effective Acclimatization
By now, we know what exactly acclimatization is and why it is so important in making your trekking adventures a comfortable success. However, the big question is what should you do for your body to start acclimatizing?
While acclimatization is an important aspect of your adventure, it is not something that can be achieved just by one or a couple of steps. There are many things which contribute to proper acclimatization. Therefore, adhere to the tips given below:
- The main thing to keep in mind is to ascend gradually. Even if it feels achievable, don’t go for rapid ascent, especially during the initial stages of your trek as it might cause trouble later. Limit the daily altitude gain to 300 to 500 meters.
- Drink lots of fluids including water, juice, or any other healthy liquid. Avoid the drinks which can dehydrate you including alcoholic beverages and caffeinated ones. Stay hydrated at all times.
- Once you have gained an altitude difference of 1000 meters, it is preferable to take a break, i.e. an acclimatization day as proper rest allows your body to adapt well. Avoid excessive physical exertion.
- Adhere to the ‘climb high, sleep low’ principle. You can go to higher altitudes during daytime, but make sure to return to a lower altitude for sleeping.
- Avoid activities like smoking or drinking alcohol as it can significantly reduce your body’s ability to acclimatize and leave you prone to higher risks of encountering acute mountain sickness.
- Consume a balanced diet, preferably carbohydrates as they are quick to metabolize and can give you enough energy required to conquer your trek.
- No matter how easy the trek might seem to you, sometimes your body might be indicating otherwise. Therefore, make sure that you listen to your body. Look for any symptoms.
- Take any mild to major symptoms including headache, nausea, dizziness, and more seriously and inform your guide and get medical attention immediately. Ascend and take proper rest.
- If you have severe issues with altitude, you can consult a medical professional before the trek and get prescribed medicines for altitude sickness including Diamox. Oxygen supplements might also come in handy.
Acclimatization During Popular Treks in Nepal
Each trek in Nepal has its own unique elevation profile as well as challenges when it comes to altitude. Therefore, you cannot apply a similar kind of acclimatization routine for every trek.
Based on the elevation profile, duration, and the terrain type of the treks, you have to select your acclimatization stops and duration at the most favorable places.
Below are the acclimatization details for some of the most popular and challenging trekking routes of Nepal to give you a basic idea of the entire acclimatization process.
Everest Base Camp Trek
One of the most iconic high-altitude treks of Nepal, the Everest Base Camp Trek is also considered to be one of the most challenging ones in terms of altitude given that it takes you to the foot of the highest peak in the world- Mt. Everest.
Spanning over 14 days, the elevation profile of the Everest Base Camp trek is quite challenging. The starting point of the trek is at Lukla at 2,840 meters (9,318 feet) and it goes as high as 5,555 meters (18,225 ft) at Kalapathhar.
For this trek, acclimatization is extremely important as even the starting point might be quite high and challenging for some people. Therefore, the Everest Base Camp trek features not just one but two acclimatization stops.
The most popular places for acclimatization during Everest Base Camp Trek are Namche Bazaar at 3,440 meters (11,286 ft) and Dingboche at 4,410 meters (14,468 ft). These are perfect rest locations with enough days and elevation gain in between.
During the acclimatization at Namche Bazaar, you hike to Hotel Everest View at 3,880 meters (17,729 ft) and return to Namche Bazaar. Similarly, on the second acclimatization at Dingboche, trekkers hike up to Nangkartsang Peak at 5,083 meters (16,676 ft) and return back to Dingboche for the overnight.
Annapurna Circuit Trek
Another trek known worldwide for its stunning mountain views and cultural experiences is the Annapurna Circuit Trek. The altitude profile of the Annapurna Circuit trek is quite unique as well.
Starting from Besi Sahar at merely 760 meters (2,493 ft), the trek takes you to the highest walkable mountain pass in the world at 5,416 meters (17,769 ft) at the Thorong La Pass. All in all, you will be covering an altitude gap of massive 4,656 meters (15,275 ft).
This gap is challenging not just for beginners but even for expert trekkers. Therefore, acclimatization becomes of utmost importance during the Annapurna Circuit Trek.
During the 18 day trek, two to three days are usually set aside for acclimatization. The most common acclimatization stops along the way are Manang, Thorong Phedi, and Tato Pani.
When taking a rest day at Manang at 3,500 meters (11,483 ft), trekkers often prefer to hike up to Gangapurna Lake which can allow them to acclimatize better.
The acclimatization day at 4,540 meters (14,895 ft) at Thorong Phedi is optional and is taken by some trekkers as the final acclimatization stop before ascending the challenging Thorong La Pass.
The rest day at Tato Pani is not necessarily an acclimatization stop but a rest stop that is taken to get rid of the tiredness of the challenging trek. However, there are a lot of things that you can do here too.
Manaslu Circuit Trek
A final addition to this list is the Manaslu Circuit Trek which also features a staggering ascent profile starting from Soti Khola at 710 meters (2,329 ft) and going all the way up to Larkya La Pass at 5,160 meters (16,929 ft).
This elevation gap of 4,450 meters (14,599 ft) is covered within a couple of weeks and thus requires proper acclimatization days to prevent altitude sickness in the remote trails of Manaslu.
Usually, there is just one acclimatization stop on the Manaslu Circuit Trek and that is in Samagaon at 3,530 meters (11,581 ft). One acclimatization day works fine if you are ascending gradually.
When in Samagaon, trekkers usually go for an acclimatization hike to Birendra Lake and even Manaslu Base Camp and return. This allows them to embrace the ‘Climb high sleep low’ principle.
However, some people also acclimatize at Dharmasala at 4,460 meters (14,632 ft) before the final ascent to Larkya La Pass. This can be a suitable option for people struggling with altitude gain.
Conclusion
Whether you are going on some of the most challenging treks in Nepal or on any beginner friendly treks, proper acclimatization is crucial to enhance your experience while also keeping you away from many health hazards.
By allowing your body to adjust to the changing altitude conditions, it not just ensures your safety but also allows you to have an experience ten folds better and successful.
While we have mentioned the acclimatization journey for some of the popular treks of Nepal, there are many others which might be on your bucket list. So make sure to understand proper acclimatization practices and plan your trek accordingly.
Remember that the main mantra is to take proper precautions, maintain a good diet, ascend gradually, and listen to your body so that if you have any kind of symptoms related to acute mountain sickness, you can immediately pause, descend, and rest before you continue the trek.
