How to acclimatize in the Alps

June 14, 2021/ Posted by Marmot Mountain Europe GmbH

Mont Blanc is the highest mountain in the Alps at 4810m and one of the hardest aspects of climbing it is getting your acclimatisation right. In this blog post I will talk you through a strategy for acclimatising for Mont Blanc, as if you can acclimatise for Mont Blanc, then you can acclimatise for any peak in the Alps following a similar (if slightly lower altitude) strategy. Yes, it is true that people arrive in the Alps from sea-level, don’t acclimatise, and get straight on 4000m peaks. Some of them do well. Many of them don’t. A few of them get dangerously sick. My advice is to ignore these people and acclimatise properly. It isn’t a chore, it involves some brilliant climbing, and it makes your chances of success and level of enjoyment sky-rocket on any bigger objectives you may have.

Take it slow

One reason for not zooming up thousands of vertical metres the day after arriving in the Alps from sea level is that you won’t be acclimatised and you could suffer from altitude sickness. The other reason is that you will be worn out before your main climb even starts! Take it slow, plan your acclimatisation to fit in with any weather forecasts and don’t be afraid to take a rest day if fitness levels or weather aren’t quite what you hoped for.

Plan of attack

Altitude affects different people differently, and even if you are experienced at altitude sometimes your body just doesn’t adjust well. Gaining not more than a thousand metres per day is a good basic strategy and gives you a chance to see how you are doing on this trip, so a rough plan of attack for acclimatising to 4800m (Mont Blanc) might go like this.

  • Day 1: Arrive in the Alps (valley level approximately 1000m) and get your kit sorted out, check the weather etc.
  • Day 2: Hike to roughly 2000m and stay at a refuge/hut or camp.
  • Day 3: Climb a mid-level route to around 3000m altitude and then return to the valley. There are hundreds of fantastic mid-level alpine rock climbs all over the Alps that are perfect for this. One of my favourites is Bienvenue au Georges V at the Envers hut (2523m) – a classic 12 pitch granite route (more info: sure you rehydrate when you get back to the valley, and I don’t mean with just beer. Whilst not getting you up to a huge altitude, this day does start the acclimatisation rolling, and gives you a good test of your current fitness level too. It’s also fun!
  • Day 4: Hike or cable-car to mid-mountain level and then approach a higher-level hut at over 2000m. Spend the night there.
  • Day 5: Climb your chosen smaller objective up to around 4000m (for example a classic peak to bag before Mont Blanc is the Gran Paradiso in Italy, it is just over 4000m and technically quite easy). Either return to the hut or return to the valley. Remember Mont Blanc at 4800m might not sound that much higher than the Gran Paradiso at 4080m, but it will feel it.
  • Day 6: Day 6: Rest day. Now you’ve done two Alpine routes you should be acclimatised fairly well, but the big one will still hurt. As well as being acclimatised, ticking off two lower-routes means that hopefully any Alpine-faff with have been dealt with, boots will have been worn in anger, crampons adjusted, gear trimmed-down and all of those ‘first route of the year’ mistakes should have been well and truly ironed out.
  • Day 7: Start your Mont Blanc or higher peak climb, usually by approaching a hut on this day to approx 2500/3000m.
  • Day 8: Summit day. Climb from your hut to the summit of your chosen 4000m peak and usually descend to the valley on the same day.
  • Beer and pizza day. Oh yes, you’ve earned it!
  • Day 10: It’s time to capitalise on your mega fitness and acclimatisation and think about approaching your next objective – whatever that may be. It is perfectly possible to acclimatise more quickly than this plan, and many people do a similar strategy but cut out the initial mid-level climb. If you’re short on time then that is an option, but if you have the chance I think this strategy makes for a fun Alpine holiday plan.

Symptoms of Altitude Sickness (Acute Mountain Sickness - AMS)

There’s good news and bad news to this bit. The good news is that symptoms of Altitude Sickness are similar to a bad hangover, and this is something that many climbers have been trained in dealing with… The bad news is that you can’t just have a cup of tea and a greasy breakfast and feel alright. The most common symptom is a headache, and if the sickness gets beyond the initial headache stage then feeling sick and being sick are also common (also common is not being able to eat food, or only certain types of food being appealing). Also add in to the mix tiredness, lethargy, dizziness/loss of balance (not a good thing on an Alpine ridge) and poor sleep. A useful too for diagnosing altitude sickness or acute mountain sickness (AMS) is a self-assessment score sheet. If you have recently ascended to over 2500m, have a headache and your total score is 3 points or more on the score sheet, then you have acute mountain sickness. Here’s a link: Lake Louise Score (LLS) for the diagnosis of Acute Mountain Sickness (AMS)

Pills and potions Whilst the Alps are low enough in general for most climbers to acclimatise naturally and fairly quickly, there are always a few people out the looking to pop a pill to speed up the process. The only drug out there that is effective in preventing AMS (that we know of) is Diamox (Acetazolamide). I’m no doctor, but here is what the website says: “This is the most tried and tested drug for altitude sickness prevention and treatment. Unlike dexamethasone this drug does not mask the symptoms but actually treats the problem. It seems to works by increasing the amount of alkali (bicarbonate) excreted in the urine, making the blood more acidic. Acidifying the blood drives the ventilation, which is the cornerstone of acclimatisation. For prevention, 125 to 250mg twice daily starting one or two days before and continuing for three days once the highest altitude is reached, is effective. Blood concentrations of acetazolamide peak between one to four hours after administration of the tablets.” The UIAA document Drug use and Misuse in Mountaineering has a lot of interesting info in it including a section on Diamox: “Despite it being used for many years nobody is exactly sure how this mild diuretic carbonic anhydrase inhibitor works in AMS prevention.” And: “a dose of 125mg twice a day, ideally started 24 hours prior to ascent, is now recommended.” Dexamethasone is another drug that you hear a lot about in mountaineering, but we won’t go in to it here as it is not used for prevention, but rather to cure symptoms of AMS. You can read more about it in both of the links above.

What to do in the event of Altitude Sickness

Go down immediately. If you or your climbing partner, or a climber that you come across is showing signs of bad altitude sickness then it is time to turn around and descend. Pushing on upwards will only make the condition worse. You might find that only a few hundred meters of descent will make a huge difference to how the sufferer is feeling. One thing worth bearing in mind is that for routes on which you are planning to acclimatize, it is worth knowing any possible escape routes, even if that means just turning around and ‘escaping’ back down the way you came! For those venturing to the Greater Ranges then a knowledge of Diamox and Dexamethasone will be essential, but are not usually carried in the European Alps.

Sleep High, Sleep Low?

Which is best, to climb high and then sleep low, or to sleep high? To go up high and just lounge around? I’m not entirely sure which is scientifically proven to be the most effective method of acclimatizing, and also everyone is different, and even the same people acclimatize differently on different occasions, but here’s what I would recommend, and this works for me and most people I know.

Climb high. Doing some exercise (climbing / walking) at increasing altitudes gets the body used to working up high and also gives you an indication of how much you are ‘feeling the altitude’. This for me is much better than just getting a lift up as high as you can and sunbathing on a terrace.

Sleep high-ish. Sleeping in some huts will increase your amount of time at altitude and will increase your acclimatization. However trying to spend the night in a high hut when you are not that well acclimatized can have a negative impact on your next day’s climbing (and if this next day’s climbing is your big objective, then a bad night in a hut can really scupper your chances or at least make you have a tougher day than is necessary) . This is because you might not sleep well (or at all) and you could get dehydrated and feel mild effects of altitude sickness instead of acclimatization. Being knackered and a bit sick is not the best way to start a big day!

If you are unsure then a good technique is to climb high and descend a fair way to sleep at the start of your acclimatization strategy and try out a night or two at increasingly high huts as you progress.

Well that’s it. That is my acclimatization plan, some notes on mountain drugs, and even a few summit and route recommendations thrown in. If you follow the advice in this article, take it slow, and then adjust to match your own body and experiences I am sure you will be able to tackle any alpine objective well acclimatized. Have fun, stay safe and see you in the mountains!

Text & Photos:
Jack Geldard

Jack Geldard
Central Europe
June, 2021
The Beta