Trends come and go in the fitness industry and most of the time, I’m happier to see them go. Every once in a while there is some validity to the method/workout/diet/equipment and it can be usefully implemented by a trainer or coach who has done the research and knows how it should fit into the program. On the other end of the spectrum, you see less reasonable individuals throw the trends directly into their program, ignorant of the effects it may yield on the trainee.
One such trend seems to be the high elevation masks. For those that don’t know, these masks are supposed to create an hypoxic(oxygen decreased) environment to stimulate affects similar to high altitude training. They also make you look like Bane, which is a just as important variable. They have become very popular in many different circles and even I fell victim to the challenge they added to workouts after receiving one for Christmas about 4 or 5 years back. I played with it for about a month before doing some digging on the subject and finding that it wasn't the best tool for my goal of crushing the upcoming Tough Mudder. So I threw it in the closet and forgot about it until recently, which is what sparked this blog post.
The Dirt
Now hypoxic training is still relatively infantile in research. Anthony Roberts has a great article on the contradictory and limited research and how it applies to these masks. One major bump in the road that he hints at, that I would like to reiterate, is that we are assuming that these masks do indeed create an hypoxic environment similarly to that of the hypobaric chambers and areas of high elevation that are used in the research. Though they do decrease the amount of oxygen in which you uptake while wearing them, they do so in a different way. It manipulates the rate at which you can ventilate, so it’s almost as if you’re forced to breath through a straw. Whereas traditional elevation training and research puts you in an environment in which there is less atmospheric pressure, making less oxygen available within the air you breath, creating a slightly different effect. There is no research(from unbiased sources) to suggest whether or not this creates any difference in physiological adaptation but I would theorize that it does. The reason I say this is the resistance provided on inhalation is going to stress muscles of respiration in a different way than breathing the thinner air at the top of a mountain.
So let's assume despite the difference in the way it decreases oxygen, that it still creates an hypoxic environment. There is also the debacle of how traditional high-altitude training is used and how these masks are used. Though hypoxic training research is limited, it has traditionally been used as a means for endurance athletes to increase their levels of hemoglobin due to the need for their systems to maintain homeostasis in the face of hypoxic environment. The main supported method of doing this is to live high, and train low(LHTL). In order for the elevation mask to replicate this, one would have to wear the mask for the majority of the day, except for when training, for about 3 weeks straight. If anyone feels committed enough to keep the mask on that long, then please tell me if it works, but be prepared to have the police called on you while in public.
Note: Of all hypoxic training techniques, the live high, train low method has been the most researched and used. One reason why endurance athletes have gravitated towards this method is that it provides the increased hemoglobin without sabotaging their workouts. When training in an hypoxic environment, work capacity becomes more limited as the system struggles for oxygen. This cuts the workouts short, and the decreased amount of work can have negative effects on other mechanisms that need to be trained. For more information you can also look here.
Though I’d like to have this as a tool to improve endurance training adaptations, I’ve found waaaay more research to support that intermittent hypoxic training yields no greater results than normoxic(training at sea level). You're better off taking it off. But this is going off of a lot of the research that used mainly aerobic-based exercise, which makes me wonder if it could have any affect when picking up heavy things?
What About Picking Up Heavy Things?
What’s interesting is that there are a few studies that delve into the influence that a hypoxic training environment can have on resistance training. One study done in Japan measured size and strength gains of elbow flexors and extensors after 6 weeks of training elbow flexion and extension for 4x10(Those dudes were bro’n out!). They found that size and strength increased significantly more in the hypoxic group and speculated that hypoxic resistance training may be a promising new method.
The study performed at the Japan Institute of Sport Science that Roberts references in his article shows that a hypoxic environment can lead to more growth hormone and more localized endurance within the trained fibers(though strength and size were the same between groups). The thing is, I’m fairly certain that you could get similar results to what these studies found by just lowering the rest periods. By depriving the body of oxygen as in the hypoxic environment, you are essentially limiting its recovery between bouts of resistance exercise. I would think that this is going to place more metabolic stress on the tissues in question and force more of an endurance adaptation to the system. After all, the glycolytic system gets replenished aerobically. What’s more, is we know that for optimum hypertrophy results in resistance training, the rest periods need to be limited while intensity under load stays fairly high. This creates more lactic acid accumulation within the tissue and in turn leads to more growth hormone response. Not to mention it can be pretty grueling and make for an intense workout, which I’m sure the hypoxic groups would attest to. What I feel would be interesting is having the subjects gauge their efforts on an RPE scale as well and compare which group perceived more exertion. My money is on the guys with less air.
So What Good Are They?
Even though it’s impractical to use an elevation mask for traditional elevation training and the fact that it may only be a question of rest periods for its effects on resistance training, doesn’t mean that we should throw the baby out with the bath water. Though I would argue that the usefulness of these masks are very limited, there could still be a time and place(though not often). It's really just up to research to further itself on the subject to really confirm when that is. But, if I had to guess:
These masks seem to have the ability to stress the metabolic system with oxygen deprivation and will raise the heart rate faster with less movement intensity. They should also tax localized active tissue more quickly due to the poor oxygen supply to the muscle. When used, it will almost be as if the athlete's VO2 Max has been temporarily lowered, causing his lactate threshold to also lower. This could result in a higher rate of blood lactate accumulation within the active tissues and all the training adaptations that go along with it. Though I would say this is typically a negative aspect, as you would get less overall work out of the athlete, if they are injured and the goal is to keep up certain aspects of their conditioning, then I could see some possible benefit to it.
You could theoretically put the injured athlete through less rigorous movements to help avoid the injury in question and yet still get a higher-intensity conditioning affect on their system. A necessity for this to work would be having the trainee wear the mask for 15-20 minutes prior to exercise to help deplete resting levels of plasma oxygen. It should also be worn for a brief period afterwards. For anaerobic conditioning, you could have the athlete do a relatively lower intensity movement and get the heart rate to the point of their lactate threshold much easier than in a normotonic environment. For the aerobic conditioning, the same rules would apply, however you would just manage their heart rate and movement variations differently. I would also consider setting the mask to a higher oxygen deprivation level for the anaerobic conditioning to limit aerobic metabolism; Whereas for the aerobic, I may start with a higher level when the mask is first put on then decrease it for the exercise to allow the aerobic pathway more capacity. The issue is that the actual carryover that this would have to maintaining the athlete's work capacity or sport-specific condition would still have to be determined through further testing and study. Until then, the above ideas are all just speculation of how it could potentially be used and should be treated as such when considering implementation. (I personally will wait for more research before throwing this at someone.)
The other aspect of these masks that I feel could be useful is their resistance affect on the breathing mechanism. This would be less physiological in effect and more neuromuscular. Since you are essentially trying to suck air through a hole or hole(s) of variable size, you are causing the muscles of inhalation to work harder. This could be very beneficial if the coach is subjective about how the trainee is breathing and includes it within low threshold work on the right individuals. Many individualshave limited diaphragm involvement upon inhalation(think neck breathers). Introducing an elevation mask along with some world-class cuing could help to reinforce proper breathing function and add some more advanced breathing drill variations to your repertoire. You could also include it in core drills and force the trainee to inhale against resistance while maintaining the proper tension for the exercise. I personally like the idea of a forced-inhalation deadbug. Whereas I wouldn't go to this variation of breathing intervention with everyone, I could definitely see a time and place.
In Summary
To sum it up, these masks do have potential to elicit very unique affects on ones training. The problem is that the physiological adaptations that will come of it are still questionable when in comparison with other methods. I believe that more research is needed to validate whether they actually replicate a hypoxic environment similarly to an actual change in elevation for the individual. I also think that whether they do or don't replicate it, the ways they are currently being used and implemented into programs by most of their users are going to elicit sub-par results when compared to other means of training. This does not mean that they are completely useless though; They still create a unique affect to alter stressors on the body physiologically and neuromuscularly. This gives them potential to be useful, though there is no substantial proof as to the carryover it will have on performance. Until that proof comes, I'm going to say these masks are just a trend.