Planning a journey at altitude: the Andes, the Himalaya and Kilimanjaro

Why altitude changes the plan

As you climb, the air holds less oxygen, and the body needs time to get used to it. The most important thing to know when planning is that altitude affects people very differently and unpredictably. Good fitness helps you walk, but it doesn't guarantee how you'll feel at 3,500 metres, and a previous trip to the mountains that went well doesn't mean the next one will.

That's why a good high-altitude route is built on gradualness rather than speed. Mountain tradition has long favoured raising your sleeping height step by step, building in acclimatisation days and, where possible, climbing higher by day and sleeping lower. What pace suits you personally is a question for a doctor and an experienced mountain guide; our job is to make sure the route leaves room for it.

At altitude, the fastest route is rarely the best one.

Peru: start lower

Cusco, the usual gateway to Peru's Andes, sits at roughly 3,400 metres, and the flight from Lima on the Pacific coast takes only about an hour. It's one of the sharpest jumps a traveller is likely to make. So many routes spend the first nights in the Sacred Valley, considerably lower, and only move up to Cusco later, once the body has begun to adjust.

It matters all the more if you plan to walk to Machu Picchu. The Inca Trail and the Salkantay route cross passes well above Cusco itself, so a trek is usually preceded by a few days of gentle acclimatisation: markets, short walks, Inca terraces. Those days aren't lost; they're part of the journey.

Nepal: on foot, with days in hand

In the Everest (Khumbu) region, height is gained on foot, so a well-planned trek is gradual by nature. After the flight to Lukla (about 2,860 m), the trail climbs over several days to Namche Bazaar (about 3,440 m), where a full acclimatisation day is usual; a similar day is often planned higher up, at Dingboche. Everest Base Camp lies at about 5,360 metres, usually reached after more than a week of walking.

Nepal's other factor is weather. Flights to and from Lukla depend on visibility, so it's worth leaving at least one or two spare days in Kathmandu at the end of the trip. If all goes smoothly, they become rest and the temples of the Kathmandu Valley; if not, they save your flight home.

Kilimanjaro: time is the greatest help

Kilimanjaro (about 5,895 m) is not technical, which makes its height easy to underestimate. Routes to the summit vary in length, and that is the most important choice: longer routes such as the Lemosho or Machame, taking seven or eight days, give the body more time to adjust than the shortest options. In our view, an extra day on the mountain is worth more here than any other day of the trip.

After the climb, plan rest, and only then a safari. A few quiet evenings below the mountain, followed by Ngorongoro or the Serengeti, let the journey carry on without haste, and without the sense that everything had to happen at once.

Bolivia and the Altiplano: high, and for longer

In Bolivia, altitude isn't a question for one part of the trip but for all of it. La Paz sits at roughly 3,600 metres, and the airport above it is higher still, so flying straight in makes for a very abrupt jump. The Uyuni salt flat and Lake Titicaca are also high, and the 4x4 crossing of the south-western lagoons climbs to around 5,000 metres in places.

So it's often worth starting lower – from San Pedro de Atacama in Chile, for example – and rising into Bolivia gradually, rather than flying directly to La Paz. Accommodation on the Altiplano is simpler, nights are cold and days long, so leave room in the route for both time and warmth.

What a well-built route looks like

From Lithuania, Peru, Nepal or Tanzania usually means connecting through one or two hub airports, with a journey of more than a day. Time-zone change and plain travel fatigue then add to the altitude. So the first day after arrival should be for rest, not ascent, and the overall length of the trip should account for getting to the mountains as well as the mountains themselves. Realistically, a journey like this needs at least two weeks, and often three.

• The first days lower down or easy: no long walks or early starts straight after arrival.
• Sleeping height rising gradually, with acclimatisation days written into the plan rather than left as 'if needed'.
• At least one spare day in reserve – for weather, flights or simply how you feel.
• An experienced local guide with the authority to decide to turn back or descend, and a clear plan for how to do it.
• Travel insurance that explicitly covers trekking at the planned altitude and evacuation from the mountains.
• Rest after the highest point: a beach, a safari or just a few slow days, so the journey doesn't end in exhaustion.

Slower, and more

A gradual high-altitude route isn't a tax paid to caution. An acclimatisation day in Namche Bazaar is a morning with your first view of Everest; a day in the Sacred Valley is a market and Inca terraces; an extra night on Kilimanjaro's slopes is another sunset above the clouds. Give the mountains time, and they usually repay it.

Tell us where altitude draws you – the Andes, the Himalaya or Kilimanjaro – how much time you have, and how you feel on long walking days. We'll shape a route where what matters isn't speed, but the journey.