How effective are altitude tents?

trainingEvery runner has heard of altitude training.  The principal is simple: go somewhere high up where the air is thinner and force our bodies to adapt to the decreased oxygen concentration.  These hypoxic conditions stimulate a release of the hormone EPO which causes a spike in the production of red blood cells, increasing the oxygen carrying capacity of our blood. To no surprise, an increased oxygen carrying capacity of our blood enhances performance by improving delivery to our oxygen starved running muscles as we push our limits. It’s legal blood doping!

Many of us have dreamed of getting this extra boost to our performance, but simply do not have the resources or opportunity to disappear to a high altitude location.

Enter the altitude tent.

The goal of the altitude tent is to simulate the low concentration of oxygen that we see at altitude without having to leave the comfort of our own home. Sleep in a tent, get the EPO production you’re after, and run faster as a result. Seems simple and fool proof, but is it?

Kenrick-Monk-6061706What does the research say?

There are some mediocre studies out there that suggest that the use of an altitude tent is beneficial. But I definitely think it is risky to believe that it’s a mindless uncalculated contribution to your routine that will make you faster no matter what.

Take for instance this study published in the Journal of Applied Physiology which is outstanding as it was double blinded with a placebo.   This means that both the subjects and the investigators did not know if they were being placed in a tent that was actually hypoxic, or just a regular tent (rooms in this case). This has definitely been a missing link in a number of other studies looking at the use of altitude tents as a blinding and placebo component to the study is so important. If I bought a really expensive tent and slept in it every night dreaming about EPO pumping through my body, how could the placebo effect not impact my mind, and therefore my training and subsequent performance?

In the study, 16 cyclists followed an 8-week protocol. Within that protocol, the athletes spent 16 hours/day over the course of 4 weeks in either the hypoxic or normal room.

This is what they found:

– In the hypoxic room group, there were a few athletes who had an increase in red blood cell concentration, a few who were unchanged, and a few who were actually WORSE.

-In the placebo group, we saw the same results! A few who showed improved red blood cell concentration, a few unchanged, and a few who were worse off.

These physiological numbers are great, but what about actual performance?

– The cycling TT that was used in the study was unchanged for BOTH groups

-The cycling economy (how efficient the oxygen they took in was being transferred into wattage output) did not change, nor did it differ in either group.

article-2103453-11CF4188000005DC-503_634x345Practical Applications:

Does this mean it’s time to throw out your high altitude tent? Not yet! What this study does show is that with this very specific protocol, odds are that you will not get a boost in performance from using it and if you do, the odds are that it will be as a result of a placebo effect.

This is interesting especially because the protocol seems extremely reasonable as a means to increasing fitness and performance. 4 weeks at altitude for 16 hours/day while maintaining training seems more than sufficient to reap the benefits.

The problem is that we don’t have definite numbers and conclusions on the dose/effect relationship to hours per day and total duration spent in a tent to stimulating the optimal red blood cell concentration. There is definitely still a good chance that we can get a boost in performance from this technology, but hopefully this study, at the very least, makes it clear that the exact protocol required to achieve this is difficult to pinpoint.

As a hobby runner, I especially like this study because it helps to put my mind at ease for yet another “gimmick.” Sometimes it’s hard to resist paying lots of money for stuff that will give us easy gains. When research like this pops up, it’s a great reminder that training, sleep, diet and genetics matter way more than everything else. Unless I’m at the pinnacle of my training tolerance, sleep and diet (which I don’t think I ever will be), I’m not going to stress about trying to sleep in a hypoxic tent!

Dr. Sean Delanghe, BSc. (Hons), DC is a chiropractorcoach, and a regular contributor to the RunWaterloo blog.

3 Comments

  • Adam Hortian July 5, 2015 2:24 pm

    Hi Sean, the placebo effect does not work in this case.

  • Adam Hortian July 5, 2015 2:34 pm

    Hi Sean. I have used altitude tents as well as trained at altitude and I find it hard to imagine that a placebo group would not immediately know that they are placed at ‘high’ altitude. The air is noticeably different. Breathing can become difficult and so can sleep. That being said, what altitude in Feet was the non placebo group set at. I have found that at times my body reacts differently to the altitude. A study should test a group like in this study but then bring them back for another study and see if the two studies under the same conditions yield the same results. Experience and majority opinion tells me there is something to using altitude tents. In fact there was even talk a few years back about there being banned by the IAAF. Silliness of course.

    • Sean Delanghe July 7, 2015 1:35 pm

      Thanks for reading Mr Hortian!..yeah I agree (and did before and after I read this study) I have no doubt for some people under the perfect conditions the tents work, it’s just that the protocol required to achieve what you want is tough to pin point, and knowing if you are a responder or not is tough to know.

      The placebo effect definitely is an important component to this. It’s funny you bring that up about how effective the blinding protocol was. Say hypothetically, the subjects had known where they are (which I don’t think happened), that would mean that the control group would have expected to do worse, and the hypoxic room group would have expected to do better. This hurts the case for altitude tents even more- since both group’s performance changed on average equally (in terms of TT and cycling economy), that would mean that hypoxic room had a detrimental impact equal to any possible placebo effect gain from a perceived difficulty in breathing. I don’t think this was the case, but again, if they COULD tell, this is what would follow.

      The other good thing is that they not only looked at performance, but also at physiological markers like Hb mass changes- which had responders, non-responders and people who got worse in both group. These results fit with what the performance outcomes showed. We can definitely think ourselves into being faster and slower, but can’t think ourselves into changing our Hct!

      The altitude used in the hypoxic rooms was 2 500m, which is standard just over that 2 400m threshold. The facility itself was just over 1 000m. Here’s full article if you want to check out their full protocol: http://jap.physiology.org/content/112/1/106

      EDIT:
      I should also mention that they tested how effective the blinding was, this is what they found:
      “The results of the questionnaires evaluating the blinding process…The large variation, with only one-fourth of the subjects guessing right at the end of the LHTL period (equal to the number of subjects guessing wrong), indicates that the blinding process was successful, and subjects were unaware of group classification”

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