Altitude at Humantay Lake
The hardest part of this day is the thin air, not the distance. The walk to Laguna Humantay is short on paper, yet it ends at a height where every step costs more breath than you expect. This guide walks through the heights and the warning signs of soroche, then what eases them. It also says plainly when to stop and walk back down.
Three heights in one day
The trip gains height in stages. Cusco, where you sleep, lies at about 3,400 m (11,150 ft), so the first breathless climb up a cobbled street happens before any tour starts. The vans unload at Soraypampa, near 3,900 m (12,800 ft). From there the path gains between roughly 300 and 400 m (about 1,000–1,300 ft) on its way to the lakeshore, close to 4,200 m (13,780 ft). Chullos begins its walk at Challacancha, a little lower, so its groups climb slightly more.
Above the water stand Nevado Humantay and Salkantay, which tops out near 6,270 m (20,570 ft). Nobody on a day trip goes near those summits. Up at the shore the air pressure is only about 60 percent of the sea-level figure, so a slope you would stroll up at home leaves fit people panting. The trail, section by section shows where the steep zigzags begin.
What soroche feels like
Around Cusco, altitude sickness goes by the name soroche. The usual signs are a headache, nausea, breathlessness out of proportion to the effort, and poor sleep. They tend to appear within hours of arriving high, and for most visitors they stay mild and fade over a couple of days. The Humantay day takes you some 800 m above the bed you slept in, so a light headache that had settled in Cusco can return on the upper switchbacks.
Some signs mean the body is not coping. A headache that keeps building despite rest, repeated vomiting, stumbling or confusion, and breathlessness while sitting still all call for going down at once and getting help.
Oxygen in the van, and turning back
Chullos Travel Peru and Inka Altitude both list an emergency oxygen bottle and a first aid kit among the inclusions, and Kantu Peru Tours carries the same pair. Oxygen buys time on the way down. It does not fix the problem so that you can carry on climbing. The remedy for altitude sickness that gets worse is losing height, and even a short descent often brings relief.
Tell the guide early if you feel unwell, before it turns into an emergency. Turning around halfway is a sensible choice, and the guides have seen it many times. The lake is beautiful, but no view is worth a bad afternoon at 4,200 m.
Two or three days in Cusco first
The listings tell you to arrive acclimatized, and the simplest way to manage that is time. Plan two or three days in Cusco or the lower Sacred Valley before the 4 am pickup. Flying in from Lima at sea level and heading to the lake the next morning is the classic mistake. Spend those first days on gentle walks and early nights, and let the body adjust before you ask anything of it.
Humantay also works as a staging post for bigger plans. Rainbow Mountain tops out around 5,000 m (16,400 ft), so many travelers do the lake first and leave a rest day before the higher hike; Humantay Lake or Rainbow Mountain? compares the two days. Kantu Peru Tours even calls its Humantay walk harder than Rainbow Mountain, though the top is lower.
On the day itself
Pace matters more than fitness. Take short steps and breathe in rhythm with them. Stop before you are gasping rather than after. Sip water through the whole climb and eat lightly at the Mollepata breakfast, and leave alcohol alone the night before. A 4 am alarm leaves most people short of sleep, which does not help, so an early night counts for more than an extra coffee. The drive from Cusco sets out the day hour by hour.
Group guides deal with altitude daily. Kantu's guide walks at the back of the line to stay with the slowest hiker. On Inka Altitude's days, reviewers single out guides such as David and Cesar, who let each person climb at their own speed instead of pushing the group along.
A group day that waits for slower walkers
Inka Altitude carries emergency oxygen and a first aid kit on its 12–13.5-hour day, and its guides have a name among reviewers for letting everyone climb at their own pace, from ~$34. Cancel free up to 24 hours before.
Coca tea and medicine
Coca tea is everywhere in this part of Peru, and many Cusco hotels keep a pot of it in the lobby. Locals also chew the leaves on long walks. It is a mild stimulant and a warming drink on a cold morning, though good evidence that it prevents soroche is thin. Coca can show up in drug tests, and carrying leaves home is banned in many countries.
Prescription medicines for altitude sickness exist. Whether one suits you, and how to take it, is a question to ask your doctor before you travel, not a tour guide or a pharmacy counter in Cusco. We give no doses here.
This page is general travel advice from people who compare tours, not medical advice. If you are pregnant or live with a heart or lung condition, speak to your doctor before booking, and do the same about any medicine you plan to take for the altitude.
Who the listings turn away
The operators set their own limits, and they are worth reading before you book. Chullos and Inka Altitude exclude pregnant travelers, and BioAndean says the same of its two-day trip. Chullos and Inka Altitude rule out respiratory problems, while Kantu and MachuPicchu Journey name heart conditions. Chullos and Kantu also set an upper age of 70, and Inka Altitude says the day does not suit people of low fitness.
Fitness wording varies by price too. Viagens Machu Picchu's day, from ~$53, walks at a relaxed pace, yet its listing still asks for "strong physical fitness", and it costs about twice as much as the main group days for a similar route. A private day such as MachuPicchu Journey's, from ~$99, lets your party set the speed; private and small-group Humantay tours compares the options.
A horse saves legs, not lungs
Local families rent horses near the trailhead for cash, and a horse carries you most of the way up, with the last steep stretch on foot. That saves a lot of energy, which helps if the altitude has you struggling. It does not change the height, though, so you still feel 4,200 m at the top, and no horse is ever guaranteed to be free when you arrive. Riding a horse up to Humantay Lake covers prices and safety.
If you know you want to ride, Cusco Grand Adventure's horseback day on GetYourGuide, from ~$86, includes the horse up from Balcompata. Its catch is the rules, since it takes no one under 10 or over 91 kg (200 lb), and you still walk about an hour down.
Sleeping at 3,900 m
BioAndean's two-day trip with a glass dome, from ~$350, puts your bed at Soraypampa, some 500 m above Cusco. Sleep is when altitude bites hardest, so the night is a stiffer test than any day trip, and the second day goes over the Salkantay Pass, roughly 4,600 m (15,100 ft) up. The trip is non-refundable, so book it only once a day trip or a few days in Cusco have shown how you handle the height. Humantay and the Salkantay trek describes the camp and the pass. For the warm layers a night up there needs, see what to wear and bring, and the best time to visit explains which months bring the coldest nights.