When you're seriously pushing the limits of your training, isn't the simple act of breathing already hard enough without strapping a mask to your face that makes you breathe through a half-clogged garden hose? The oxygen deprivation or "altitude simulator" mask makes you look like the skinny-fat version of a Batman villain, but it can also do damage the cardiovascular system and breathing mechanics.
It's actually difficult to correlate studies that evaluated the efficacy of various forms of hypoxic training such as high elevation and closed chamber, oxygen-deprived rooms. The research is spotty on specifically using an oxygen deprivation mask itself, and it wouldn't do any good to make ballpark comparisons with this style of training. The mask truly stands alone in its stupidity.
With all the oxygen deprivation mask's shortcomings, there was actually one meta-analysis that showed that training in an oxygen-deprived environment may have the ability to reduce waist circumference and effectively reduce arterial stiffness. I'm sure that's exactly why so many Average Joes are strapping this thing to their faces while repping out supersets or running around the track. For their arterial health.
Bad Posture and Deep Breathing
Something I often see in my clinical practice is an alarmingly-high rate of dysfunctional, and sometimes even painful, breathing patterns directly attributed to posture or a lack of it.
Posture with increased kyphotic spine positions, internally rotated and protracted shoulders, and a forward head position predispose our respiratory muscles to overexertion on a frequent basis. And this debilitating postural cycle is just when we're sitting still. Think about what happens as we include training volume, intensity, and exercise choice into the equation.
Posture obviously has a major carryover into training and performance, and it can actually predispose certain regions of the body, such as the lumbar spine and shoulder region, to increased rates of injuries. Using an oxygen deprivation mask with an individual who already has dysfunctional posture and poor mechanical breathing patterns is a recipe for disaster.
Take Off the Mask
In a society that "likes" social media pictures of NFL pros and MMA stars hitting the treadmill wearing this dysfunctional gimmick, I challenge you to break away from the crowd. Master your posture, enhance your breathing strategies and techniques, and only then might you even begin to think about taking the next step to train in a legitimate hypoxic environment.