It is important to prepare well for any Inspired Adventure, as good preparation generally equates to having a more successful and enjoyable experience. When travelling to high altitude there are additional factors to consider, and this month our friends at Sydney Altitude Training share their knowledge of high altitude trekking and maximising your summit success chances.
When you travel higher the air pressure gets lower, making the air less dense or ‘thinner’. The reason for this is as you ascend air molecules are further apart (the air gets thinner) and your body gets less oxygen for every breath you take.
If you’re heading to altitudes upward of 2,000m this presents a major physiological challenge to the body. There is nothing more fundamental to human survival and physical performance than getting sufficient oxygen into, and around to the body’s tissues, including muscle. Another important factor is temperatures are usually much colder the higher you go.
Although trekking at high altitude is never going to be a ‘walk in the park’, the good news is that given sufficient time your body will adapt fairly well so you can reach your desired destination.
|What is high altitude and approximate oxygen availability?|
|High altitude 2500 – 3500 metres||(75% to 66% of oxygen available at sea level)|
|Very High altitude 3500 – 5800 metres||(66% to 50% of oxygen available at sea level)|
|Extremely High altitude beyond 5800 metres||(less than 50% of oxygen available at sea level)|
What happens to your body at high altitude?
When exposed to thin, high altitude air the body can’t absorb and deliver enough oxygen to meet its demand, causing blood oxygen saturation levels to drop below normal. In an effort to acclimatise and make up for the short fall the cardiorespiratory system jumps into action. As you ascend you will find yourself breathing faster and deeper, you will also notice your heart rate and blood pressure will increase well above what it does for the same exercise done at sea level (e.g. walking at 4 kilometres per hour). As a back up to these immediate adaptive responses, lowered blood oxygen saturation levels stimulate the kidneys to increase production of the hormone erythropoietin (EPO) leading to greater red blood cell production and increased oxygen carrying capacity.
It’s important to note that individual tolerance to high altitude conditions varies considerably. Some people acclimatise rapidly, whilst others can develop symptoms of mild acute mountain sickness (AMS) at altitudes of above 2,000m.
Climbing too fast and ascending too soon
When people set out on high altitude adventures they usually have two key goals; first, make it to the goal destination (e.g. Uhuru Peak at the summit of Mt Kilimanjaro or Everest Base Camp) and second, have fun doing it. AMS can, and does get in the way of many people achieving one or both of these goals.
Most people going above 3,000m experience symptoms of mild AMS. For some this will feel like a mild hangover while others will feel awful. Two key things you can do to reduce your chances are:
- Ascend as slowly as possible (ideally no more than 500m per day, although this is not always possible).
- Don’t expect to walk as fast at altitude as you do at sea level. This is particularly important for people who, at sea level, have high levels of physical fitness and like to lead the pack. AMS is common amongst young, gung ho fit people, especially men who want to get to the top of the mountain first. So ‘fitties’ beware, there is no relationship between higher level physical fitness at sea level and your tolerance to high altitude.
If you don’t acclimatise properly, you greatly increase your chance of developing AMS, or even worse, HAPE (high altitude pulmonary oedema) or HACE (high altitude cerebral oedema).
For more on HAPE and HACE click here.
Tips for a successful adventure:
Maximise fitness – Whatever your susceptibility to AMS, being strong and fit beforehand will be of great benefit, just don’t race to the top!
Pre-acclimatise – Get a running start by exposing yourself to oxygen levels found at altitude by training at a simulated altitude training facility, such as Sydney Altitude Training.
Pace yourself – Slow your pace as you gain elevation and focus on maintaining a steady breathing/stepping rhythm as you gain altitude.
Use your lung capacity – When you notice any breathlessness, turn your attention to taking deeper breaths and slow the pace until you regain a sustainable pace. This is especially relevant on steep sections.
Stay hydrated – Thinner air is typically drier air, and you lose a lot of fluid very quickly at high altitudes. This is the main reason people get headaches when they go to even moderately high altitudes.
Carb up – Due to reduced oxygen availability at altitude the body uses relatively more carbohydrate to fuel exercise. Be sure to keep carbohydrate high on the menu.
Stay warm – Air temperature drops about 6-6.5 degrees Celsius for every 1000m of elevation gain (e.g. a comfortable 25 degree day at 1,500m will be more like 15 degrees at 3,000m).
Happy feet – Wear appropriate, sturdy and worn-in hiking boots.
Are you travelling to high altitude soon? Sydney Altitude Training currently have a SPECIAL OFFER for Inspired Adventures participants.
Deal includes 10 x 1 hour sessions for each person PLUS two complimentary Baseline Altitude Response Assessments. Valid for bookings until 31 October 2012.
To retrieve offer, include the code InspiredAlti10 in the business field of your enquiry as below by clicking here or visiting http://sydneyaltitudetraining.com/contact-us/