In the grand scheme of various sport training techniques and equipment that have been passed down and developed over the centuries since the Ancient Greeks thought it was a good idea to smother themselves in olive oil and wrestle naked, the use of high altitude training masks is in it’s infancy. What are they, I hear you ask. Well, just picture yourself wearing Bane’s mask from The Dark Knight Rises whilst trying to do Fran and you’ll start to get the idea. In truth, they are meant to replicate the design of traditional altitude training, as I’ll explain below—minus the actual altitude. How convenient! So how exactly do they work? What are their benefits? And are they actually effective?
High Altitude Training Masks: Definition
As the name suggests, high altitude training masks seek to replicate the effects one would have from training at altitude. Competitive athletes have trained at high altitude as a means of improving their potential for years.
Benefits of high altitude masks
In fact, 95 percent of all running medalists at the world championships and the Olympic Games since 1968 have either lived or trained at altitude. This is because when the human body is exposed to hypoxia (oxygen reduced environments), it struggles to produce required amounts of energy with less available oxygen. As such, the body is forced to acclimatize to the lower levels of O2, which triggers the onset of a range of physiological adaptations geared towards enhancing the efficiency of the body’s respiratory, cardiovascular and oxygen utilization systems. These include an increase in the number of small blood vessels (which helps to transport 02), an increase in buffering capacity (ability to manage the build up of waste acid) and changes in the microscopic structure and function of the muscles. After a couple of weeks training at altitude, athletes then return to sea level, fresh off the positive effects of their training which allows them to compete at a higher level.
Disadvantages of high altitude masks
It’s not all gravy. Acclimatization to high altitudes can cause some damaging side effects that cancel out its benefits. For example, the increase in red blood cells makes blood thicker and can make blood flow sluggish. This makes it harder for your heart to pump round the body, and can actually decrease the amount of oxygen getting to where it is needed. At very high altitudes (>5000m), weight loss is unavoidable because your body actually consumes your muscles in order to provide energy. Additionally, the body cannot exercise as intensely, loss of appetite is common, there is an inhibition of muscle repair processes and there is the risk of altitude sickness. Not to mention the logistical difficulties of travelling to or living in high-altitude locations for extended periods of time when training for competition!
How does high altitude mask work ?
Unsurprisingly, some super-smart sports nerds wanted to find a way to replicate the effects of altitude training, while still being at sea level. However, high altitude masks are just a simulation of elevation. What the mask actually does is force you to breathe against resistance. So instead of thinning the oxygen in the air (as is what happens at high altitude), it simply takes greater effort to breathe—which makes sense, as having anything covering your mouth during a workout would make it tricky to get oxygen into your lungs.
And that’s sort of the point. The pulmonary resistance created by elevation masks conditions the lungs, strengthens the diaphragm (a muscle that controls your breathing) and promotes increased lung capacity by forcing you to inhale fuller, deeper breaths. What’s happening is that as your body begins to adapt to the resistance (i.e. the mask) your lungs will be trained to take deeper breaths and use oxygen more efficiently. The lining in your lungs will stretch out, increasing the alveoli’s (tiny air sacs in the lungs at the end of the smallest airways, where the exchange of oxygen and carbon dioxide takes place) surface area, allowing for more blood flow (and an increase in red blood cells) and oxygen transportation.
There are limited studies on the design and effects of elevation training masks, though one study from the Northern Alberta Institute of Technology conducted a training study of high intensity interval training (HIIT) while wearing the masks. 8 men and 6 women performed cycle ergometry twice a week for five weeks while wearing the masks. The participants were pre and post tested on measures of pulmonary and cardiac function. The study showed an increase in VO2 max (maximal oxygen consumption) and power output, and a decrease in heart rate responses following exercise. The study concluded that the elevation training masks are equally effective as the more traditional method of high intensity interval training while wearing self-contained breathing apparatus (SCBA). However, SCBA’s are expensive, heavy and linked to heat stress, which would make an elevation mask a more attractive option to use for training.
Despite the apparent positive benefits of training with a high altitude training mask, it is not without criticism. When an athlete trains at altitude, they will be inhaling air that has the same percentage of oxygen in it as at sea level. What makes training at altitude valuable is that the pressure of the air at altitude is far lower, meaning that there are fewer air molecules present in general, including oxygen (though the percentage of these molecules that are 02 remain the same). So if an athlete is training with the mask at sea level, they will still be exposed to the same percentage of oxygen, and more importantly, the pressure of the air will remain the same—negating the positive effects of training at altitude. Furthermore, the bulk of altitude training evidence points to prolonged exposure, or immersion, as being the key factor to improving performance. A few sessions a week wearing the mask will not recreate that effect, one must either live in a high altitude region for a while (Big Bear in California is one famous high altitude training site) or must sleep or spend a good portion of the day in a hyperbaric chamber that replicates these conditions, and I’m guessing you don’t have one of those lying around.
Ultimately, high altitude training masks do have some positive effects in regards to VO2 max, power output and heart rate, which are all factors in performance. In that sense, it would be worth utilizing one for a while, testing yourself on a benchmark WOD than retesting after a period wearing the mask. But if you are looking for the full effects of training at altitude, than the best option is to simply take yourself up there.
Photo courtesy of Naval Surface Warriors/CC BY-SA 2.0