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Jean Christian LICHAIRE
Guide de Haute Montagne
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Altitude and medical advice

Altitude and medical advice

Climbing the Mont-Blanc (4807 m), the Mont Rose (4633 m), or the Grand Paradis (4061m), les highest summits in Europe, can be done by any person at a good fitness level. However these races should not be banalised as, according to the heights, the dangers due to the change in the weather conditions may suddenly turn to be great.

These ascents require a good endurance, habituation to altitude and a training to basic safety techniques and ice field progression. This experience is gained by practicing high mountain races. We advise as well to attend a race preparation day.

The Mont Blanc is not advised to young people under 18 years old.

Mountain environment constraints.

As a newcomer in a particular world, the mountaineer will have to get used to several types of aggressions due to the environment change.

  • Hypoxia or decrease in oxygen pressure in the air,
  • A new physical activity
  • A climate or food change.

Hypoxia is an unavoidable constraint: there is no simple technical means to replace the physiological adaptation.

However, the preparation, the equipment and your guide’s experience will enable you to reduce the drawbacks due to the changes in physical activity, climate and food.

Altitude-induced hypoxia and organism’s reactions.

The decrease in oxygen pressure in the ambient air causes a reduction in the number of available oxygen molecules needed for the functioning of each cell: this is the definition of hypoxia.

When the organism is confronted with this unusual environment, it develops physiological mechanisms so as to return the cell oxygenation toward normal or at least allowing a normal life.

The adaptation

It is the first stage that everyone can live when using cable cars or during a high mountain route. The body’s most common response to high-altitude conditions is hyperventilation i.e. raising the depth and rate of breathing and so the heartbeat.

These reactions are good as they enable an increase in the oxygen quantity delivered each minute to the cells.

Acclimatization and acclimation

If the body is exposed to the altitude more than a few hours, the organism triggers adaptation mechanisms more economical, which will progressively replace hyperventilation and tachycardia.

This physiological compensation will only be efficient if the exposure is progressive and prolonged enough. All these mechanisms are called acclimatization which, when it is really effective, leads to acclimation.

This state allows a person coming from the sea side to have a physical activity in heights. The time it takes and the quality of this acclimatization is very different from a person to another.

Physical performances in altitude

Living quietly in altitude is not a problem but as soon as the body increases its energy needs, e.g. during a climbing, the lack of oxygen turns to be a performance limiting factor.
At the summit of the Mont Blanc a person only has 70% of his/her capacities at the sea level.

Hydration is essential in the mountains.

If you don’t want to carry a too heavy backpack, without being afraid of the terrible ‘heat hit’ so frightening for the soldiers during a forced march, the old experienced guide has got a good strategy :

  • Giving up any idea of performance, the mountains are not a stadium !
  • Adaptating the progression rythm and the clothing so as to avoid any excessive sweat,
  • Having regular breaks to have a drink and share this friendly moment with the group
  • ‘Drinking before being thirsty’ : here is the advertising slogan of the main two water bag makers… If the message is sometimes worrying, it is crystal clear though :  drinking or weakening : you have to choose.

Anyone practicing an enduring or resisting sport has to drink as soon as the effort lasts more than 30 minutes otherwise his/her physical performance will reduce. Practicing mountaineering or climbing is not exception to the rule. Actually the weather conditions, generally warm (temperature are hardly ever -2°C [35.6°F] in Algeria, except at night, or in Libya), increase the water losses.
Basically the organism consists  (approximately 2 thirds) of water and the fuel making plant cannot lack water. However our body at rest loses approximately 2.5 liters of water and sometimes much more at effort hence being exposed to dehydration (or lack of water).
Any loss of 2% of the body weight, i.e. less than 1.5kg for a person weighing 70 kg [155lb], causes a decrease in physical performances of 20% ! Therefore it is easily understandable that a climber that hydrates and compensates his/her losses is in better condition than the one who neglects this reality.

How do we lose water ?

Dehydration : decrease in hygrometric pressure combined with hyperventilation increase the water losses by the respiratory tract and bring about dehydration.
The water loss can stem from breath : the air expired for each move is saturated in moisture ; from perspiration : through the skin pores even at rest ; from sweat : during an effort or in a warm ambiance, the pits, the forehead and the back sweat a lot according to the effort, the ambient temperature and each person.

How to replace the lost water ?

By pure water with more or less added sugar in low quantity (50g per liter) so as to get an isotonic drink (same concentration as the liquids inside the body). Why sugar ? Because it is the basic fuel of the cell. So, in such a situation glucose, fructose and maltose match perfectly.
The optimal concentration of diluted sugar is 50gr per water liter since it is close to that of plasma (inside liquid in which the cell is): it is isotonicity.

What are the symptoms of dehydration ?

  • weight loss
  • ‘late’ thirst
  • heavy fatigue
  • dry mucus membranes
  • lower skin elasticity
 if it gets worse

  • consciousness troubles like lethargy
  • quick and shallow breathing
  • weak and rapid pulse
  • hypertension (less than 10)
  • hyperthermia

Which water bottle to use ?

Standard,  isotherm or Camel back water bottles ?
Beware! The main drawback of Camel back water bottles is to ice in altitude or during very cold weather.
It is advised to have a Isotherm water bottle above 3500m in heights.
For the ones who prefer to have a backpack with a built-in hydration bag of a sufficient volume (2 to 3 liters) equipped with a nozzle : the main two makers regarding the value for money are Hydrapak® and Camelback®, first manufacturer on the market. These two companies offer a complete and technical range of products including full equipped backpacks.
Basically the only way to compensate the loss of water is to hydrate regurlarly so as to make sure to have enough fuel !
1 or 2 liters of water is the minimum to do a race (keep champagne for the arrival).
A good assessment of an optimal hydration is the proof of the diuresis (every 2 to 3 hours people need to pee !) proving that there is an optimal blood flow in the kidneys, the key organs of dehydration. Unfortunately no that easy for you, ladies !

Acute Mountain Sickness

The AMS is neither a disease nor a defect . It is just the sign of an incomplete acclimation to the altitude.
One person in two is subject to AMS over a certain altitude.
The troubles arise 4 to 8 hours after arriving in altitude and more usually from 3500 meters.

  • headaches 96% of cases
  • insomnia 70% of cases
  • lack of appetite 38 % of cases
  • nausea 35 % of cases

Usually these signs are combined with dyspnea, dry cough and sometimes vertigo.
Even the best climbers may feel the AMS. If you feel one of these troubles your acclimation is not complete.

3 golden rules

  1. Don’t go up too fast.
  2. Going up high enough to get used to it.
  3. Do stay too high too long.

Your guide is able to advise you on the best technique to adapt to altitude as well as the appropriate treatments to adapt yourself.