Do Elevation Training Masks Simulate Altitude Training?

Update! 

With what little research we had back at this this same time in 2015, we concluded that it was “unlikely” that elevation trainings masks actually simulated altitude training. (see original post below)

It did not make sense that it would work conceptually or physiologically for aerobic variables, but perhaps more advantageous for respiratory muscles, because it is just harder to breath in these things. But, at that time there was little research. I predicted that more research would come out in 2016-2017. 

With a quick search, I found 3 studies.

One study looked at 24 moderately trained individuals, who did high intensity cycling for 6 weeks with or without the mask.² There were no difference in VO2max, pulmonary function, or hematological variables. The authors conclude, “Wearing the ETM while participating in a 6-week high-intensity cycle ergometer training program does not appear to act as a simulator of altitude, but more like a respiratory muscle training device,” – confirming our previous assumptions.

Two studies looked at ROTC cadet training for 6-7 weeks, and also found no differences in VO2max.^3,4 Both concluded that training with the mask was not beneficial in aerobic outcomes.

There were also several really good student research abstracts that found the same thing.

Interestingly, I am not sure why someone would think wearing the mask during weight training would be a good idea, unless they are protective against some noxious odors at the gym. But, there was one study that tested the effects of the mask in 20 recreational weight lifters during 2 weight training sessions plus a maximal effort sprint.¹ The researchers concluded that the mask did not hinder them completing the training sessions, however “wearing the ETM does appear to attenuate [reduce] the ability to maintain working velocity during training bouts and negatively influence ratings of alertness and focus for task.”

In conclusion, there is now more evidence in support that elevation training masks DO NOT simulate altitude training. So, I have now changed this post from “plausible” to “busted.” 

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References

1. Jagim, A. R., Dominy, T. A., Camic, C. L., Wright, G., Doberstein, S., Jones, M. T., & Oliver, J. M. (2017). The Acute Effects of the Elevation Training Mask on Strength Performance in Recreational Weightlifters. Journal of strength and conditioning research.
2. Porcari, J. P., Probst, L., Forrester, K., Doberstein, S., Foster, C., Cress, M. L., & Schmidt, K. (2016). Effect of wearing the elevation training mask on aerobic capacity, lung function, and hematological variables. Journal of sports science & medicine, 15(2), 379.
3. Sellers, J. H., Monaghan, T. P., Schnaiter, J. A., Jacobson, B. H., & Pope, Z. K. (2016). Efficacy of a ventilatory training mask to improve anaerobic and aerobic capacity in reserve officers' training corps cadets. The Journal of Strength & Conditioning Research, 30(4), 1155-1160.
4. Warren, B. G., Spaniol, F., & Bonnette, R. (2017). The effects of an elevation training mask on VO2Max of male reserve officers training corps cadets. International Journal of Exercise Science, 10(1), 37-43.

Original Post

Elevation training masks originally claimed to provide adaptations normally experienced at elevations above 2,000 meters, but at sea level. You have probably seen them before, as they are showing up in ads and television commercials. They are popular among Crossfit athletes, NFL athletes have been spotted wearing them, and I just saw one being used in the recently released “Creed” movie trailer.

From http://www.trainingmask.co.uk/

The mask fits snuggly to the face. There are small holes where air gets in and out, but small inhale/exhale pieces supposedly simulate high and very high altitudes. You wear it while you exercise, which makes it harder to breathe.

Sounds like fun, right? But, do they work like we were training at elevation?

No, but let's look at why. 

First, A Quick Lesson: “Live High, Train Low”

At sea level, the air we breathe is 20.95% oxygen. However, at higher altitudes, such as 2,500 meters the percentage of oxygen is only around 15.3%. The less oxygen (%) makes it harder to breathe, which you might have experienced on a short walk or hike on vacation in the mountains.

However, if we lived at this higher altitude, our body would adapt. Specifically, our body would release a hormone, called erythropoietin (EPO), which quickly increases the production of red blood cells. If you remember from science class, red blood cells carry oxygen throughout the body. 

Well, these extra red blood cells and the ability to carry extra oxygen would also help our ability to perform better during an aerobic competition, such as a marathon or triathlon. So, scientists first started having athletes live AND train at high altitudes to get these aerobic adaptations.

However, they quickly found that the living part worked fine, but training at high altitudes did not work well – mainly because the athletes could not train hard enough to get the much needed training benefits due to the lack of oxygen in the air.

Ingeniously, they figured out that if you live high, you get the adaptations you need, but then you need to train at a lower altitude to get training benefits. This is where the famous phrase, “live high, train low” came from, and a major reason we have our Olympic Training Center in Colorado Springs. They can live at a higher altitude, then take the bus down to a lower altitude to train.

Elevation? Training Mask

Now that we know the basics, you can see why the mask does not simulate altitude training?

1. These masks are not changing the percentage of oxygen in the air, since we are breathing the same air. Thus, oxygen remains at 20.95% of the air we breathe in or inhale, and does not simulate oxygen content at altitude. We need hypobaric chambers for this effect.
2. The ‘live high, train low’ prescription states NOT to train high. If the masks did simulate altitude training, then we would probably not prescribe them during training.

What Does the Research Say?

Oddly, there is very little research, but I predict 2016-2017 will be fruitful for new research.

For now, we know:

1. The mask might slightly lessen the percentage of oxygen we breathe out or expire, suggesting that we might try to retain a little bit more oxygen while wearing a mask (15%) versus no mask (16%) – although staying within normal ranges (15-18%).²
2. The mask appears to reduce peripheral capillary oxygen saturation (SpO2), which is an estimation of the amount of oxygen in the blood. We are usually between 95-100% saturation, but the mask will reduce this to 90-92%, indicating slight hypoxia.²
3. However, this hypoxia might simply be a result of all the carbon dioxide that you have to breathe in while wearing the mask – like the classic trick of breathing into a brown lunch bag when someone is hyperventilating.
4. One study has found that the amount of oxygen breathed in (VO2) with the mask, was not different than without a mask.²
5. One study found a slight 3% improvement in change in VO2max in a group that wore a mask versus a different group of people who did not wear the mask.⁴ However, because the groups were different people, we cannot confirm that the mask was behind any changes.
6. I found no data that these masks produce the same adaptations as training at altitude, such as change in erythropoietin or red blood cell count. These effects are probably unlikely, due to the mechanisms of hypoxia, but is ripe for future research to help us answer this question.
7. The mask could possibly be acting as ‘respiratory muscle training’ (RMT), since it seems to make breathing more difficult on the muscles that help us inspire and expire air. Thus, some benefits could be seen in respiratory muscle strength and endurance.^3,4
   These types of results are now the main focus of the original elevation training mask, with little to no focus on the ability to produce the effects of training at altitude.
8. Finally, several other claims are made that do not have support at this time, so should be taken with caution until we know more: improved mental focus, reduced medication and symptoms, improved quality of life, and enhanced ability to recover from injuries and training.

Potential Detrimental Effects of Hypoxia

If you think about using these masks, remember that it is a form of hypoxia – meaning there is less oxygen reaching our bodies’ tissues. As you know, we need oxygen, so anyone wanting to train in hypoxic states, need to consider the potential detrimental effects.

“Overall, the negative effects of hypoxia [lower cardiac function, reduced metabolism and muscle function] seem more pronounced at high to extreme altitude, albeit that sleep and immune function of some athletes are likely compromised even at moderate altitude.”¹

Conclusion

Elevation training masks originally proposed to produce similar aerobic training effects at sea level, as those experienced while training at higher altitudes. However, the mask does not simulate altitude training, which is dependent on altering the percentage of oxygen in the air.

Rather, the mask makes it physically harder to breathe, reducing the amount of total air that can be breathed in, and increases the amount of carbon dioxide that is breathed in. Subsequently, the mask might help train the respiratory muscles, which is now the main focus of many training mask companies (not simulating altitude training).

I presume much more research will becoming out after next year, and I will provide an update as we learn more.

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References

1. Gore, C. J., Clark, S. A., & Saunders, P. U. (2007). Nonhematological mechanisms of improved sea-level performance after hypoxic exposure. Medicine and Science in Sports and Exercise, 39(9), 1600-1609.
2. Granados, J., Gillum, T., Castillo, W., Christmas, K., & Kuennen, M. (2015). ‘Functional’ respiratory muscle training during endurance exercise causes modest hypoxemia, but overall is well tolerated. Journal of Strength and Conditioning Research. Ahead of Print.
3. HajGhanbari, B., Yamabayashi, C., Buna, T. R., Coelho, J. D., Freedman, K. D., Morton, T. A., ... & Reid, W. D. (2013). Effects of respiratory muscle training on performance in athletes: a systematic review with meta-analyses. The Journal of Strength and Conditioning Research, 27(6), 1643-1663.
4. Probst, L. (2015). Effects of the elevation training mask on maximal aerobic capacity and performance variables. Master’s Thesis, University of Wisconsin – La Crosse.

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