Athletes are always looking for the next great supplement, training program, or device to enhance their performance and make them bigger, stronger, and faster than the competition. One of the latest training trends spreading through gyms around the world are elevation masks.
Everyone one from NFL running backs to soccer moms can be seen experimenting with the interesting looking contraption hoping to gain the benefits of high altitude training simply by strapping on some crazy looking face shield. While you might think you look like a badass (or Bane from Batman) with a training mask at the gym, the reality is that you’re getting very little, if any, real benefit from it, and look exceptionally goofy to boot.
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Let’s take a look at why that elevation mask isn’t all it’s cracked up to be!
Why Elevation Masks?
So, why have so many people started embracing the elevation mask trend?
Well, in the simplest terms possible, anytime an athlete thinks something, no matter how crazy it may seem, can give them an advantage (no matter how small) over the competition, they’ll do it. This is why you’ve seen so many professional athletes training at high altitudes during the offseason.
The reason they’re training at these higher altitudes is that when training at high altitudes, your body is exposed to a lower atmospheric pressure as well as a lower partial pressure of oxygen (the total units of oxygen per defined area). In simpler terms, the higher in elevation you go, the thinner the air is, which makes breathing considerably more difficult. Exposure to this reduced amount of oxygen in the air leads to less oxygen in the blood, which means even less of it is getting delivered to and used by your muscles.
Now you can begin to understand why it’s so hard for teams visiting stadiums in Colorado to perform at the same level compared to when they’re playing in their home stadium that’s closer to sea level.
Prolonged exposure to this lower partial pressure leads to some pretty interesting adaptation by the human body - it increases the myoglobin/hemoglobin content of the blood and capillary density throughout the body, which leads to increased oxygen transport to the muscles.  As you’re probably aware, increased delivery and utilization of oxygen throughout the body leads to better performance and endurance, so you can see why so many elite-level athletes are embracing altitude training.
Now, where elevation masks come into the picture is that they supposedly provide the same benefit as training at altitude by limiting the amount of available oxygen during training, or any other time you’d choose to wear it. This sounds pretty good for marketing material when you first hear it.
Your body is getting less oxygen, so it must adapt and get used to performing with less available oxygen. But, that’s not exactly what happens according to the research.
Why Elevation Masks Don’t Work
Simply wearing an elevation mask for 45-60 minutes 4-5 times per week while you’re training at the gym isn’t going to give you the benefits of training and living at altitude. You see, it takes week, and possibly months, of constant exposure to high altitude for your body to adapt and respond to the reduced oxygen content of the air.
Additionally, until your body actually does adapt, your performance decreases. In fact, VO2 Max falls about 10% every 100 meters you train above 1100 meters.  To further compound things, your training intensity and capacity is significantly lower initially training at altitude, meaning you have less effective workouts, slowing progress and limiting gains. 
But, the real reason elevation masks don’t work, and why you don’t need to train with them, is that they don’t actually lower the oxygen concentration in the air, the way high altitudes do. Elevation masks simply reduce the amount of air you can breathe. So, while the mask may make it feel like you’re training at reduced oxygen, by limiting the amount of air available and making you re-breathe air higher in carbon dioxide, all it’s really doing is making exercise harder, significantly limiting your performance.
Research confirms this as well. A recent 2016 study involving 25 “moderately trained” college students (16 males, 9 females) sought to investigate whether or not training with the Elevation Training Mask 2.0 (ETM), developed by Training Mask LLC, in Cadillac, Michigan, improved several endurance variables consisting of: 
- Ventilatory threshold (VT) - a measure of when breathing is too fast for your body to properly use the oxygen you're taking in
- Respiratory compensation threshold (RCT),
- Maximal heart rate (MHR), and
- Peak power output (PPO)
Students completed a 6-week high-intensity cycle ergometer interval training program with training sessions held twice per week. Each session lasted 30 minutes in length. The mask group trained at increasing simulated altitudes over the 6 weeks, which were as follows:
- Week 1 -- 914 m
- Week 2 -- 1829 m
- Weeks 3 & 4 -- 2743 m
- Weeks 5 & 6 -- 3658 m
24 of the 25 students completed the 6-week training program, with one female student dropping out due to a knee injury. Following the post-training assessments, researchers determined that both the mask and non-mask (control) group saw significant improvements in VO2max and peak power output (PPO). However, only those students wearing the masks saw significant improvement in ventilatory threshold (VT) and respiratory compensation threshold (RCT). 
This lead researchers to conclude that wearing the mask could have the potential for use when it comes to improving performance, but not for the reason you think. There were no hematological variables pre to post training, which means there was no increase in hemoglobin/myoglobin content, erythropoietin (EPO), or capillary density as you would get from training at altitude. Summing up their findings, the team of researchers concluded:
“Wearing the ETM did not improve lung function, inspiratory muscle strength, or stimulate changes in hemoglobin or hematocrit levels. The ETM does not simulate altitude, but works more like a respiratory training device.” 
So, why did the mask group experience some improvements that the control group did not?
Essentially, by limiting the amount of air that they could breathe, their respiratory systems had to work harder and over time the strength and endurance of their respiratory system improved, but there were no increases in red blood cell count or oxygenation of the blood. So, should athletes start turning to these masks to build up their endurance?
No, as endurance performance is not limited by the amount of air you take in, but by the amount of oxygen in the air. When training with less overall air, all you’re effectively doing is limiting your own performance and training capacity, ultimately hindering your progress in the gym. Additionally, these masks serve no purpose whatsoever for individuals solely looking to improve their body composition with resistance training (bodybuilding, powerlifting, Olympic lifting).
Weight lifting is mostly an anaerobic process (doesn’t require oxygen), so oxygen utilization won’t be a major factor in determining performance. But, if you’re restricting overall air intake, breathing, in general, becomes more difficult. So those mini-breaths you take during those 20-rep squat sets reduce your ability to create adequate intra-abdominal pressure, restricting stability and overall performance.
Bottom line, if you’re just hitting the gym a few times per week to lift the weights, there is absolutely NO NEED WHATSOEVER to train with an elevation mask.
But, let’s say that you decide to embrace altitude training 100% and go live on a mountain in some foreign country for a year or so or by one of those in-home hypobaric (high altitude) chambers and spend 20-22 hours per day in there five to seven days per week. It’ll still take you at least four weeks before you fully adapt to the hypoxic environment.
Even then, once you’ve acclimated and gotten the benefits of training at altitude, most of those physiological adaptations your body has made disappear within four weeks or so. Plus, most research on hypoxic training yields little to no benefit for athletes. 
Rather than worrying about increasing your red blood cell count, capillary density or oxygenation levels, most non-Olympic level athletes (i.e. everyone that’s currently using these elevation masks) would be better served by improving the efficiency of their musculoskeletal system. Doing so allows you to utilize more oxygen from the air you normally live in.
In other words, work on maximizing your fitness (resistance training, high-intensity interval training, etc.) in your present surroundings to the fullest extent possible, and leave the gimmicks alone.
References1) McKenzie, D. C. (2012). Respiratory physiology: adaptations to high-level exercise. British Journal of Sports Medicine, bjsports-2011.
2) Naeije, R. (2010). Physiological adaptation of the cardiovascular system to high altitude. Progress in Cardiovascular Diseases, 52(6), 456-466.
3) Vogt, M., & Hoppeler, H. (2010). Is hypoxia training good for muscles and exercise performance? Progress in Cardiovascular Diseases, 52(6), 525-533.
4) McGinnis, G., Kliszczewicz, B., Barberio, M., Ballmann, C., Peters, B., Slivka, D. et al. (2014). Acute hypoxia and exercise-induced blood oxidative stress. International Journal of Sport Nutrition and Exercise Metabolism, 24, 684-693.
5) Buchheit, M., Hammond, K., Bourdon, P. C., Simpson, B. M., Garvican-Lewis, L. A., Schmidt, W. F., et al. (2015). Relative Match Intensities at High Altitude in Highly-Trained Young Soccer Players (ISA 3600). Journal of Sports Science & Medicine, 14(1), 98.
6) Porcari JP, Probst L, Forrester K, et al. Effect of Wearing the Elevation Training Mask on Aerobic Capacity, Lung Function, and Hematological Variables. Journal of Sports Science & Medicine. 2016;15(2):379-386.
7) McLean, B. D., Gore, C. J., & Kemp, J. (2014). Application of ‘live low-train high for enhancing normoxic exercise performance in team sport athletes. Sports Medicine, 44(9), 1275-1287.
8) Truijens, M. J., Toussaint, H. M., Dow, J., & Levine, B. D. (2003). Effect of high-intensity hypoxic training on sea-level swimming performances. Journal of Applied Physiology, 94(2), 733-743.