What if we told you that you could get fitter and faster, just through sleeping in your own home? Well using an altitude tent has the potential to do just that. Photos by Daniel Gould

Product Overview

Overall rating:

Score 8

Altitude Tent and Everest Summit Hypoxic Generator


  • Can make you fitter


  • Can disrupt sleep and relationships
  • Results are not guaranteed
  • Expensive


Altitude Tent and Everest Summit Hypoxic Generator

Price as reviewed:

This product is featured in: How far would you go to be a better cyclist?.

In order to establish what the performance benefit of an altitude tent might be, Cycling Weekly got hold of a unit from the Altitude Centre.

What is it?

By sleeping in a tent at a simulated high altitude, you reduce the amount of oxygen you are able to breathe in, which forces the body to increase its red blood cell count. Then, when you train back at sea level, you are able to compete more effectively because a greater amount of oxygen is now being delivered to your muscles than before.

>>> Bike Fitting. Which approach is best?

Not everyone has the luxury of training at altitude, so many people, cyclists in particular, hire altitude tents or hypoxic chambers which they will sleep in to get the same effect. Some cyclists have been known to train in them, with some pitching them up over their desk at work.

I hired an altitude tent and slept in it for a month. We all want to be faster and are looking for ways to become faster and fitter. Altitude training can do that, so I decided to try sleeping in an altitude tent to see if an amateur club cyclist, such as myself, could benefit and see a physiological improvement. I was also keen to establish how easy it is to use and live with. Would it disrupt my sleep? Would my girlfriend mind?


It is probably worth consulting your partner before sleeping in an altitude tent

>>> The three Rs of recovery

What does it consist of?

Firstly, there is a tent. Our test model is designed to fit over a queen sized bed, with your mattress inside, although other sizes are available. Some tents are large enough that you can comfortably set up an exercise bike or treadmill inside.


Our tent was designed to fit over a queen sized bed, with the mattress placed inside

The next crucial piece is the hypoxic generator. This is connected to the tent via a tube, and it is this unit which regulates the atmosphere inside the tent.

The tent simulates the atmospheric oxygen concentration at 2,700 metres above sea level — roughly the height of the Stelvio Pass.

You can use the control to set the altitude you want and it ranges from 0m to 3,962m, which is roughly from sea level to the height of the Eiger in Switzerland.


The unit is simple and features a range of altitudes you can set it to

The other bits of kit are an air filter which fits over the end of the tube and an Oximeter. The filter cleans the air of pollution, pollen and microbes, whilst the Oximeter is used to monitor your heart rate and oxygen saturation levels.

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The oximeter tells you your heart rate and blood oxygen saturation

In healthy individuals at sea level, blood oxygen saturation (SpO2) is typically 98-100%. Whilst at 2350m our saturation is likely to drop to around 87-92%. Our heart rate is likely to be higher too.

The guidelines for using the tent suggest you record your blood oxygen saturation and resting heart rate every morning.


The air filter

How much does it cost?

In the world of elite sport, marginal gains and Olympic gold medals, the price of renting or hiring an altitude tent almost becomes insignificant to professional athletes. But to the club athlete looking to boost their performance in a Grand Fondo or race, the price may be more restrictive.

>>> How to plan your training

The system we have on test can be rented from the Altitude Centre for £450 a month or purchased outright for around £4,000. That is a serious amount of money for most of us.

How does an altitude tent make you fitter?

In 2012 Sir Bradley Wiggins spent considerable periods of time living at altitude on Mount Teide, Tenerife. This training proved very successful, with Wiggins going on to win the Tour de France, Olympic gold and a whole host of other stage races.

The idea is that you sleep in the tent at simulated high altitude and continue training at or around sea level. The tent simulates altitude by reducing the oxygen content of the air you breathe.

At sea level air contains 21% oxygen, whilst at 3000m there is effectively 14% oxygen. The composition of the air remains the same at altitude, what differs is the partial pressure, meaning the molecules are further apart (i.e. the air is thinner).


The tent shown fitted over a bed

Dr Mark Cole, a lecturer in integrative physiology at the University of Nottingham School of Life Sciences informed us that “live high train low makes sense from a physiological perspective, because from the limited studies that have been done, it seems to offer the biggest effect. It enables you to maintain high intensity training loads, that you wouldn’t be able to do at lower oxygen.”

With regards to how to body responds, Dr Cole told us “the kidneys sense that there is less oxygen available and that kicks off a whole series of cellular events in the kidney which results in cells in your bone marrow being released into the blood stream, which then promotes growth of red blood cells. You may get a measurable response within 10 days to two weeks.”


Although pictured in isolation, the tent is designed to be fitted over a bed with the mattress inside.

How did we test this?

In order to see if this tent will give us any improvement we needed to do some tests before and after sleeping in the tent. Cycling Weekly spoke to leading experts to establish the sorts of things we should look at. Dr Max Testa, Chief Medical Officer of the BMC Racing Team told us “you can do tests before and after to see the effects of altitude, you can do heamatocrit, but a haemoglobin test is most important.”

Dr Cole informed us, “haematocrit and haemoglobin are the primary indicators of exercise capacity because they have been shown to be some of the limiting factors, in terms of supplying oxygen to muscle.

“Haematocrit gives you a measure of how many red blood cells you have in a set volume of blood. A ballpark figure for humans is 43% in 1mL of blood, but it can vary considerably. Heamoglobin level is intrinsically tied to how many red blood cells you have, because the haemoglobin is contained within red blood cells and is the part which actually carries the oxygen, so it can be offloaded at the cells.”

Our Experiment

  • A baseline haematocrit test (volume of red blood cells in blood).
  • A baseline haemoglobin test (protein molecule in red blood cells that carries oxygen to body tissue and returns carbon dioxide back to the lungs).
  • A baseline 20 min FTP (functional threshold power) test
  • A baseline ramp test at sea level and at altitude.

I slept in the tent for a month then repeated the above tests post tent.


Thanks to the University of Nottingham for the blood tests

As a disclaimer, it is worth noting that this experiment is by no means definitive and not the most scientific, considering we only have a sample size of one.

While different protocols for using altitude tents exist, I couldn’t test everything in the time available. Factoring this in, I decided to follow the protocol that the Altitude Centre advises. This involved sleeping in the tent for one month for typically 8-9 hours a night, and not training in it.


The hypoxic chamber at the Altitude Centre was set to 15% oxygen

Results and discussion

Before I get on to the numbers, I should say that the tent wasn’t the easiest piece of equipment to get along with.

I’m a good sleeper, but I found the tent hot and dry and my sleep quality was affected. Sleep plays a huge role in recovery after cycling, so this was potentially a big issue.

I did however focus on trying to get plenty of sleep, probably about 1.5 hours more a night than normal.

This required the discipline of not watching Newsnight, procrastinating on the internet or getting lured in by the start of Predator at 10pm on BBC1 (we’ve all been there).


Sleep can be disrupted

I should also point out that the tent did create a hypoxic environment and I measured my blood oxygen saturation every morning using the oximeter. My Sp02 was 85-89% when in the tent and when not in the tent my blood oxygen was 99-100%.


I kept a diary and measured my blood oxygen in and out of the tent every morning

Test  Pre Tent  Post Tent
Haematocrit 0.487 L/L 0.483 L/L
Haemoglobin 162 g/L 164 g/L
20 min power test (Watts) 304 W 337 W
My Weight 68 Kg 67 Kg

The blood test results suggest there was no change in my haematocrit or haemoglobin levels, as the slight differences lie within the realms of experimental error.

However, I did feel in great shape after sleeping in the tent and my 20 min power was significantly higher, at just over five watts per kilogram.

To add further weight to this, I took part in three criteriums after sleeping in the tent and placed second, fifth and third.

_MG_0123 2

One of my blood samples

Although no physiological change was observed in my blood values, it may not necessarily mean there was no improvement. “Plasma volume [the fluid red blood cells are contained in] can increase with training, resulting in a lower haematocrit,’ says Dr. Mark Cole, who oversaw the testing.

“This may be working against any increase in haematocrit resulting from hypoxia, resulting in a neutral blood result.”


FTP and ramp tests are hard!

When I performed my second ramp test in the altitude chamber, I was able to reach the same result at 700m higher than before. This could have been down to physical adaptations, improved fitness, a placebo, or combination of these.

Is it worth it?

It’s hard to tell, some individuals appear to benefit more than others. Dr Cole explains that “the response to altitude between individuals varies a great deal — with the limited amount of properly conducted research available, some people show a very strong response, others show modest or no improvement in performance.”

Dr Testa pointed out that “there is no one size fits all; some people don’t have a big response, they are insensitive”. Whereas “other people are quick responders. Some recreational guys tell me that they have spent five days at altitude and they come back feeling that everything is much easier.”


Sleeping in an altitude tent is likely to affect your relationship as much as your sleep!

From my experience I would suggest you factor in the quality of sleep you will get in the tent, as it can be affected. Convincing a partner to use the tent too is not going to be easy, and the high cost can’t be ignored.

Although my FTP increased significantly it is important to think about where that improvement came from. I was training, sleeping and eating well during the experiment.

In addition, I was highly motivated and felt good. My improvement could potentially have just been down to a well structured, good quality block of focused training.

There is potential for a placebo effect too. Placebos can be a powerful thing and are currently at the cutting edge of science. Peer-reviewed studies repeatedly show that if you believe something is going to make you better/faster, it often will. I may have benefitted from a placebo effect.

Thanks to Dr Mark Cole and the University of Nottingham School of Life Sciences for their help in this feature. For more information on renting or buying altitude systems, head over to the Altitude Centre.

Five breakfasts for cyclists


Has the potential to increase performance but results are not guaranteed. Requires some trial and error and is expensive. For most of us, bigger gains can be made by losing a few kilograms

  • gbshaun

    Correct Todd. It’s the PARTIAL PRESSURE of OXYGEN which the body responds to, and that can be reduced by lowering the total pressure OR by reducing the % of the molecules which are oxygen.
    We have more recently been creating systems for pilot training for the Navy, FAA etc.
    1 minute in a normobaric hypoxic enclosure at 30,000′ and anyone who doesn’t understand partial pressure will soon get a very convincing lesson !

  • Todd Munk

    Based on what I’ve read, I don’t think this is correct. The lower amount of oxygen (vs. lower pressure) creates the same effect physiologically. The body still ‘thinks’ it’s at 7000 feet. Correct me if I’m wrong.

  • sam calder

    The benefit of altitude training comes from the partial pressure of air across your lungs. Sleeping in a tent that just lowers the oxygen levels will do nothing to improve your hematocrit etc. You would need to be in a depressurised chamber (the opposite effect to what divers use) Anyone who actually buys one of these has just wasted £4k.

  • Gordon Morris

    While I’ll pass on the oxygen tent, I’m compelled to give kudos to the author of the article. Highly informative and very witty. Was a great read; thanks for taking the time to write!

  • Hoosierdaddy

    How did you make your own? I’d love to save money.

  • Jimmy Dee

    What a ridiculous article.

    So you did a month of testing, except you slept 1.5 hrs more per night on average – which you say is an important part of recovery (an it is).

    You found zero difference in haematocrit and haemoglobin, but felt more alert and performed better with short duration training.

    Answer: the hypoxic tent did sweet F all, but you were getting 15-20% more sleep and felt better as a result.

    You should definitely try training in the tent because simply sleeping in it won’t do anything. Your body is at rest at night, so it doesn’t really have a strong need for red blood cells. While training, the body needs more red blood cells

    That’s why guys with big muscles often have really big blood vessels in them.

    Nobody ever got really big blood vessels by sleeping more. Hence, putting your body in stress (need red blood cells, not enough, make MORE) will create change. Lowering your oxygen density while your body’s needs are at their lowest will do nothing but waste your time and money.

    None of this is rocket science. I guess common sense really isn’t that common.

  • gbshaun

    Much as I’m flattered, I tend to agree. This model is no more advanced than the first ones I made in 1998, and less portable. In 1998 it would have justified a very high rating as it was so much better than any other altitude training option available to most people, but not in 2015. The larger cubicle tents are far more comfortable and air-conditioning is an inexpensive add-on option to avoid the heat/humidity issues.

  • Ian Buck-Barrett

    Unsurprisingly this adds nothing to our understanding of altitude training. Poor science, no control group, not blinded, and only 1 participant. How can you possibly score the product as 8/10?

  • gbshaun

    That’s not a protocol I’d ever recommend, but if it works for you, go for it. Most users stay around 7-9k’. Personally i ended up at just 8000′ where i may not have got the maximum altitude stimulus, but my sleep quality and recovery was better even than at sea-level, meaning I could train harder.
    Re Hypobaric Vs Hypoxic, Whether up a mountain, or in a hypobaric chamber as i took into the 1996 Olympic village with me, or whether in the far-cheaper altitude tent i first made the following year (I remember brainstorming with Obree in our room in the Village),… a lung full of air all contain the SAME amount of oxygen. It’s simply a cheaper, more convenient way of creating that environment for athletes who don’t have access.

  • Ian Buck-Barrett

    You are absolutely right that this is a hypoxic chamber and not a hypobaric chamber. We can debate all day long but the bottom line is the evidence is poor. In some studies some people improved, some got no better and some got worse. I have a little knowledge in respect of this as I have a post graduate qualification in mountain and altitude medicine.

  • Martin P. Hoff

    Actually that is not correct and very misleading. The gas in hypoxic tents is not found anywhere in the world “naturally” as you claim. In air, the oxygen percentage is 21% – and this is the same if you are by the beach or on the top of Mount Everest. The difference in pressure makes the air take more space on the top of a mountain (the molecules are further apart), and when breathing this air the body gets less oxygen due to this effect. Hypoxic tents typically pump in hypoxic (low oxygen) air into the tent, so that the effect on the body is similar – i.e. less oxygen per breath – however this is an artificial gas with oxygen down to 12% which does not exist anywhere on the planet. So to justify the use of hypoxic tents, the argument is that the EFFECT of breathing this gas is similar to the EFFECT of being on the top of a mountain. But then why not just use EPO instead? The EFFECT of using EPO is exactly the same.

    Wake up and smell the morality.

  • gbshaun

    You are correct about the level of well-designed studies, though there have sadly been a number of poorly-designed ones (such as this, if they consider it a study) whose protocols left little chance of success. But that is a long long way from meaning that the systems provide no benefit. Indeed it is well established that altitude exposure causes positive adaptations, the important details though are making a commitment to the protocols which will realize these benefits, and a system design which doesn’t have a detrimental effect on things like comfort.
    The athletes who have done it correctly have made significant gains, comparable to actually living somewhere like Park City (where there’s lower altitude training opportunity). With the simulated altitude they have been able to achieve this without having to quit school or leave home.
    What is surprising is, even to this day, how many elite athletes STILL are leaving the benefits of altitude exposure on the table.
    On anything one COULD wait until all the conclusive studies have been done, but that approach just means you’re the last one to the party. Those who benefit the MOST from any technical or training method advance are the early adopters. I recall a world championships (1990) where only half the pursuit riders had aero bars!

  • gbshaun

    Martin, the ethical question as been addressed extensively, and over many years since the tents were first available in 1998. All the system does is filter out a portion of the air (in this case some oxygen) to create an environment that’s naturally found elsewhere in the world, enabling athletes everywhere the same access. This is exactly the same as someone in a very hot and humid environment using an air conditioner to filter some of the water molecules out of their air to create an environment naturally found elsewhere. Athletes use one or the other, or both, because sleeping in that atmosphere is beneficial.
    There is a distinction made between directly manipulating the body physically or chemically, or subjecting it to an external environment, especially one that some athletes already have convenient access to.
    On the grounds of fairness, well the USOC chose to build its training center in Colorado Springs, an altitude most countries simply don’t have. Simulation systems are not inexpensive, but they are far cheaper than a few multi-week-long trips there for sea-level residents.

  • Erez Levin

    After 8 weeks (dec14/jan15) using my TrainingPeak, I reached 16,000 feet as per the protocol, the major change I felt was the ability to keep the high watt power longer, and a “no need” to recover after a strong climb sprint – the breathing was easy and more energy was delivered to the muscles. improvement was by 20 watt but at lower heart rate (20 bpm less)

    I will surely use this for another cycle in mid season b4 major races

  • Martin P. Hoff

    You should really touch abit more on the controversy associated with these tents. E.g. The usage is illegeal in Norway, Italy and in olympic villages. This is artificial manipulation of rhe blood and really not very different than blood-doping.

  • Ian Buck-Barrett

    The evidence for the benefits of these devices is poor at best. There are no well powered double blinded randomised control trial which have shown consistent benefit. In all likelyhood any benefit is placebo effect.

  • gbshaun

    As someone who knows a little about these tents (since 1997) I’m going predict because of poor equipment (too small a tent, not air conditioned) and unrealistic protocols and testing parameters, a rather unpleasant experience and disappointing results.
    Altitude tents DO work, and can provide most of the gains which residents of altitude locations can enjoy for free, but ONLY if you have a good setup where you’ll sleep comfortably such that you can make it a regular part of your ongoing routine. Would you evaluate the validity of weight training by doing it for 4 weeks and then measuring your cycling performance? And forget Hct (and possibly Hgbn), this is unlikely to change from just 8 h/night for a month.
    “20% improvement”???? No way. But even if someone just made 2% gain (= far more realistic for an altitude tent), for an advanced rider that’s probably more improvement than all the rest of their training that year will produce.

    Shaun Wallace