These days, most of us are wearing masks, at least in public places. But do training masks, and even our personal protection masks, have fitness benefits? Here's what science says about restricted breathing and exercise.
You've probably seen those sleek, slightly intimidating, tight-fitting masks worn by UFC fighters like Diego Sanchez, Tyrone Woodley, and Carlos Condit, celebrity actors like Michael B. Jordan in the movie Creed, and maybe even some extreme workout enthusiasts at your local gym who appear to be the exercising equivalent of the villain Bane from Batman’s The Dark Knight Rises.
From the looks of NFL players, Ironman triathletes, BJJ champions, MMA fighters, boxers, Crossfitters, and beyond, these masks—which come in a variety of colors, shapes, and sizes—are staying trendy longer than I'd anticipated.
I got a mask back in 2013, and then a device called a Powerlung shortly after that. I fully expected them to disappear within the year—not because they lacked science or had been proven ineffective but mainly because they looked silly and felt terrible to use. I mean, exercise is hard enough without feeling smothered while you do it. Training masks are just a fad, right?
Well, maybe not.
The difference between resisted breathing, restricted breathing, and hypoxia
Let’s do an experiment: Put your fist up to your mouth like you're pretending your hand is a trumpet. Now, breathe in and out through the tiny space between your fingers and your palm. That's resisted breathing. You can think of it as weight training for your lungs.
Now, go for a swim. (Or, if a swimsuit or pool isn’t handy, imagine going for a swim.) Experience what happens when you breathe every five or seven strokes instead of every one or two. That’s restricted breathing. It sends a clear message to your body that oxygen molecules are few and far between.
Finally, let’s say you climb a mountain or crawl into an altitude tent (a fancy tent that basically sucks some of the oxygen out of the air you’re breathing). That’s hypoxic training, in which the air is truly thinner and you’re pulling less oxygen into your body with each breath.
Some notes on breathing apparatuses
An oxygen concentrator is a machine that pressurizes the air in a room and separates the nitrogen from the oxygen, which creates a high concentration of oxygen and a low concentration of nitrogen.
A hypoxic generator works the same but in reverse. This machine has been modified so the exhaust (the high nitrogen gas) is directed to the person using it via a tube. Both are pretty cool machines, but hypoxic generators and oxygen concentrators are expensive. Like, thousands-of-dollars expensive.
So, back to the less expensive masks. Since a mask neither restricts how often you can breathe nor reduces the partial pressure of oxygen in the air you're breathing, a training mask would only fall into the first category of resisted breathing. The idea behind using a device that encourages resisted breathing is that it may enhance your endurance or cardiovascular performance by strengthening your inspiratory and expiratory muscles, which would then increase something called your “ventilatory capacity” (basically, your lung size).
While masks can certainly be effective for improving ventilatory capacity, they don't result in the same physiological adaptations as true hypoxic training.
The problem with masks is that even though you're wearing that scary-looking training mask as you sprint on the treadmill at the gym, the air you breathe is still approximately 21 percent oxygen—with the same partial oxygen pressure present as whatever altitude you happen to be at—as everyone else at the gym. Basic masks simply restrict your breathing by covering up your mouth and nose and controlling your airflow with larger or smaller holes. So while masks can certainly be effective for improving ventilatory capacity, they don't result in the same physiological adaptations as true hypoxic training.
Resisted breath training research
There has actually been quite a bit of research on respiratory muscle training, which involves inhaling through any type of device that encourages your inspiratory and expiratory muscles (your intercostal muscles, serratus muscles, and diaphragm) to work harder.
The research was somewhat inconclusive until a 2013 review called “Effects of respiratory muscle training on performance in athletes: a systematic review with meta-analyses,” which concluded that resisted breath training may indeed boost cardiovascular and endurance performance at sea level, particularly in sports such as swimming, during which breathing frequency is limited. But unfortunately, the boost was small, and so were the sample sizes used in the studies.
However, a different story emerges when we turn to investigate what happens during athletic performance at altitudes where breathing and oxygen utilization become even more crucial due to lower amounts of oxygen in the atmosphere. In this scenario, you tax your breathing muscles far more intensively, and an argument could be made that the more conditioned these breathing muscles are via the use of something like a resisted breathing mask, the less prone to fatigue you and your breathing muscles will be.
In 2016, a study called “Respiratory Muscle Training and Exercise Endurance at Altitude” tested this hypothesis. Researchers subject participated in 30 minutes of resisted breath training three times a week for four weeks. It’s important to know that they weren’t using a training mask in this study, but rather a special breathing device that allowed for something called “voluntary isocapnic hyperpnea respiratory muscle training” (VIHT training). Basically, this means the carbon dioxide levels in the study subjects' blood remained relatively constant so they wouldn't become dizzy or faint.
Following the resisted breath training, study participants were able to last a shocking 44 percent longer in a cycling test to exhaustion, while a control group and a group didn’t improve one bit.
Then, researchers tested the subject's performance at an altitude of 12,000 feet. It turns out that following the resisted breath training, the participants were able to last a shocking 44 percent longer in a cycling test to exhaustion, while a control group and a group that did a “sham” (or placebo) version of the breath training didn’t improve one bit.
The idea behind the improvement in the resisted breath training group is that their respiratory muscles were able to withstand fatigue for a longer period. With less blood being shunted to the respiratory muscles, that meant more was available to hardworking body parts like the legs.
Interestingly, the same group of researchers performed a separate study in which they used a similar protocol to test cognitive function at altitude. The problem is that cognitive processing speed and working memory can be significantly compromised during exercise in thin air, which makes perfect sense since there's less oxygen getting to your brain in conditions where the air is thinner. After four weeks of resisted breath training, both cognitive processing speed and working memory during exercise at 12,000 feet were improved, possibly due to better tolerance of carbon dioxide buildup and also possibly due to more “resilience” to the discomfort brought on by thinner air.
And one final quick point, as highlighted in a 2013 study: When you increase the amount of carbon dioxide in front of your face (which happens when you wear a training mask), you actually increase the carbon dioxide content of the air you breathe back in. That, in turn, can decrease the percentage of oxygen you take in per breath and thus increase your tolerance to the higher amount of carbon dioxide that tends to accumulate during a difficult exercise.
Is there a workout benefit from personal protection masks?
The fact that many of us have started wearing masks (and have been encouraged to do so by many of the world's leading health organizations) led me to wonder if there were some similar benefits to exercising while wearing our PPEs.
If you have tried to go for a run or a bike ride wearing a mask—even a homemade one—you've likely noticed how much harder you have to work to get a good breath. You've probably also noticed that you get tired sooner and your heart rate climbs faster.
I enlisted the help of Dr. Belisa Vranich, author of Breathe: The Simple, Revolutionary 14-Day Program to Improve your Mental and Physical Health, to answer the question of whether we get some benefit out of this inconvenience or if we're just suffering more to remain safe.
Is there a benefit from wearing something like a mask that forces your inspiratory and expiratory muscles to work harder? No, there's no benefit because most people are not breathing with the correct breathing muscles to begin with. Most people are breathing with auxiliary muscles. These are muscles that are not meant to be primary breathing muscles; they're neck, shoulder, and upper chest muscles. So now these muscles are being taxed even more.
Putting a mask on when you're a vertical breather (and most people are) just leads to fatigue and stress.
The vertical breath that is with auxiliary muscles is also an inefficient breath. So, it doesn't bring in a lot of air and it forces you to breathe faster to get the air that you need. And it also puts you more into a sympathetic state. So, putting a mask on when you're a vertical breather (and most people are) just leads to fatigue and stress.
The solution to this is to change your breaths to be a diaphragmatic horizontal breath by taking the breathing IQ. The breathing IQ is a measure of thoracic excursion, and it lets you know if you are in fact using your primary breathing muscles. If you are using your diaphragm and your primary breathing muscles, then you need to strengthen them. And that way, when you are wearing a mask or when you're just doing an endurance sport, you'll not fatigue as quickly.
One of the things I talk about is how inspiratory and expiratory muscle training helps with endurance. There is where most of the research is, which says that if you train your breathing muscles, it will definitely affect your performance, especially with endurance sports.
When it comes to strength training, training your breathing muscles helps tremendously because it can make for better intraabdominal pressure and protect your spine. It can also help you not fatigue between sets (and hence not get injured) and really give you more awareness about how to stack your diaphragm and your pelvic floor, get that zone of opposition, and [create] better protection for your spine. And then, in pursuing sports, it will help you find that natural respiratory pause that makes you more precise. Then, of course, there's the whole topic of recovery, resilience, and inner game mental health as well.
What I learned from Dr. Vranich is that, much like those scary masks I mentioned at the beginning of this article, we sadly aren’t getting much (if any) fitness boost from wearing PPE masks. The resistance is too minimal to actually act like resistance training for our lungs. But, on the flip side, learning to breathe better and more effectively (from books like hers) will help us in both our sports performance and in our ability to be more comfortable wearing a mask in public places.
Should you restrict your breathing?
Ultimately, it appears that if you’re going to be competing or exercising at sea level, the use of a restricted breathing training mask may give you only a slight boost in performance. If you’re going to be performing at altitude, you get a far more significant positive effect in both cardiovascular and cognitive performance.
Of course, the effects aren’t as pronounced as they would be if you had used an actual hypoxic altitude training device, slept in an altitude tent, or moved to the top of a mountain to train for your event. And even though simply putting a cloth mask on isn’t enough, it would appear to be enough to encourage me to use my fancy Batman villain mask or the Powerlung (which were both purpose-built for the job).
I will practice breathing exercises in my living room with the dual goal of being more comfortable in my PPE while also crushing it at the gym and on the racecourse.
Also, considering that we can all practice breathing better by just reading a book, with no fancy gear at all, I'm going to keep following Dr. Vranich’s lead. I will do as the good doctor says and practice breathing exercises in my living room with the dual goal of being more comfortable in my PPE while also crushing it at the gym and on the racecourse.
This article was originally written by Ben Greenfield. It was substantially updated by Brock Armstrong.