OK, this is a weird one . . .

The BBC reports on a strange placebo effect in the world of sports that even the scientist investigating it can’t explain.

The Pico Simón Bolívar is one of the highest mountains in Colombia. Near the top, there is only half as much oxygen as at sea level, a dizzying 5,500m (18,000 feet) below. The air up there makes it hard to walk and causes fatigue and headaches, so the body tries to adapt: breathing rate increases, the heart beats faster and blood vessels expand to get more oxygen to tissues.

As you might expect, giving someone an oxygen tank to breathe from will reverse these changes. They’ll quickly feel less tired and their head will stop pounding as their heart rate and breathing return to normal. What you wouldn’t expect is that you can achieve exactly the same thing if the oxygen tank is a fake – it’s empty.

Fabrizio Benedetti is the scientist behind these experiments. Based in Italy at the University of Turin, he has given people placebo oxygen on mountains in Colombia, Alaska and his laboratory in the Alps and observed the same thing –fake oxygen tanks can mimic the effects of the real thing.

The effect only works if an actual oxygen tank is given to the subject a few times first, before it’s switched for a sham one without them knowing. That way, their bodies are expecting to receive an oxygen hit. Remarkably, although the tank is now empty, it can still boost physical performance on a lab-based high altitude walking exercise. The question is – how?

“This is the one-billion [dollar] question,” says Benedetti. “There is no oxygen in the blood, there is no oxygen in the body, but you can get the very same effect as real oxygen. The real answer is we don’t know.”

There’s much more at the link, including speculation as to the cause of this phenomenon – but that’s all it is.  At present, there’s no solid evidence or proof of what’s going on.

I find this fascinating.  Could this sort of “placebo effect” be triggered during a sporting event, to provide a boost equal to a performance-enhancing drug, but without the illegality?  Could it be used in the context of military operations, to give troops in combat a boost to their performance that lasts just long enough to triumph over the enemy?  The possibilities are endless.



  1. Actually, I think that already happens in various areas. The human body is remarkably 'adaptable' to keeping itself alive…

  2. Way more than just weird! The mind 'thinks' the extra o2 is going to be there so the body reacts as it is?

    Again, we just need to know enough to ask the correct questions… I wonder how far reaching the answers to this question will be?

  3. I don't find it surprising at all, if the question is giving the O2 bottle to someone who has become "trained" to the idea that the bottle gives relief.

    What I find surprising is that the body's sensors don't detect they're getting nothing from the bottle and they're still short of oxygen, causing the symptoms to return. Let's face it; if you don't have enough oxygen at some point you're gonna die. I'd expect that their bodies would behave as if there's enough oxygen but after a while would notice they're still short of oxygen and the symptoms would return.

    If I'm not mistaken, that 18,000 ft altitude is around where the base camps are on Everest, where climbers will stay for a week or two without bottled oxygen to acclimate to the thinner air. IIRC, they go to one and possibly two more base camps to acclimate and tend to use Oxygen bottles only for the last few thousand feet

    [sarcasm]Hey, I read a book once, I must be an expert [/sarcasm]

  4. Hmmm. Probably works on the same effect as breathing in a paper bag when hyperventilating. Reset on CO2/O2 balances, forcing the body to cope. Slowing the panic, which pushes hyperventilation more than actual low 02 or high CO2.

    It makes sense, once you think about it. It's not the actual low 02 that gets you, it's the panic and fear and all the stupidity that is associated with panic and fear.

    And it explains why meditation or calming prayer or whatever the person uses to control panic and fear can result in a person surviving in a low 02 or high CO2 environment.

    Mind over matter. Which the zen masters and other spiritualists have been telling us for multiple millennia.

    What next? Scientists discovering towels are dirty because they smell? (Actually, about 10 years ago, scientists determined that towels are dirty when, yes, they smell. Duhhhhh…)

  5. It irks me to no end when I read "Near the top, there is only half as much oxygen as at sea level,"

    Because that is absolutely NOT accurate. The air one breathes at altitude is still 21% oxygen (well, 20.9%, to be more precise), just as it is at sea level.

    What's different at altitude is the density of the air. The molecules are farther apart, due to less pressure on them. It's like being underwater… The further down you go in the water, the more pressure being placed upon you. And as you go up, the pressure is reduced. As the pressure is reduced, the air bubbles in your blood expand, making the molecules of air in those bubbles to be farther apart.

    Regardless, at altitude, there's no less oxygen than at sea level… it just takes more effort to get those oxygen molecules into your lungs.

    (Spent years climbing mountains for fun…)


  6. In the 1980s I had a patient with Emphysema, lip and fingernail beds blue labored breathing, and the ambulance O2 tank was empty. Put a mask on the patient clicked the delivery gauge several times. At first the patient said it wasn't helping (still blue color) so I warned the patient that I could only turn it up a little more because I didnt want him to stop breathing because of his Emphysema. Some more clicking of the valve and just two minutes later the blue went away and the breathing was normal. the patient said they felt much better. The trainee with me couldn't believe it but all was documented on the report. Oh there was a significant change in prepping the ambulance for use after this.

  7. I fail to see how one can not know the O2 tank is empty. Having scuba dived many times, often with 2 or more tanks for extended dives, trust me, you know when the tank is empty and the demand valve does not deliver any air.

  8. Kind nit picking and maybe it was a translation fault.
    If the tank was empty- it would be a vacuum.

    As I learned working in the natural gas industry. A pipe is never "empty" if it's not a vacuum.

  9. Calling b.s., and betting the originally claimed effect is non-reproducible.

    Change my mind.

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