NYX Endurance

Ok, But Which Mask?

Part II of Dr. Jeff’s Mask Experiment
By: Dr. Jeff, NYX Endurance Athlete & Physician

Last month you learned that wearing a mask or gaiter while exercising near other people is important to your health and to the health of those around you. With so many choices on mask/gaiter styles and fabrics, which one is the best to use? I attempted to answer this question by personally performing a couple of crude studies in addition to reading a lot of articles in the legitimate medical literature. In Part 1 of my study, published last month in the NYX Endurance Newsletter, I describe the candle test. This month I would like to report about Part 2 of my study: performance while running.

Since at NYX we embrace the darkness, I used the opportunity to run in the dark (to check off that Bingo Box) and test several masks and gaiters at the same time. I tested a total of 13 face coverings starting with the gold standard, a personally fitted N95 mask from my hospital, and ending with some commercially available gaiters (6 gaiters, all from different manufacturers and all made from different fabrics). I had a head-mounted light source and a chest-mounted GoPro camera angled up toward my mouth. The goal was to see if the light would illuminate respiratory droplets coming from my mouth as I ran and to capture them on video. Nothing fancy and no lasers involved. It is important to realize that my observations only pertain to easily seen respiratory droplets and NOT microscopic aerosolized particles.

I ran 0.25mi with each mask on at approximately the same pace and on the same course to keep as much constant as possible. The first run was my “control run” without a face covering. After I started running, it was very easy to see the spray coming out of my mouth. It is amazing how much we don’t see during the day while running (and presumably cycling) that becomes apparent only at night when a direct light is present. Also surprising was that the spray generated did not spot up my running glasses and I could not feel any moisture hitting my face. Had it been daytime, I would have been oblivious to it all. The fitted N95 performed as expected…NOTHING got through. My glasses did fog up very slightly but it was minor. It was definitely not comfortable to run in however. I then tested loose-fitting KN95, surgical, and double-layer cloth masks. They ALL performed very well but they all fogged up my glasses considerably. Then came the gaiters. I was most interested in testing them since they are the most convenient to use for an athlete. I was very surprised that they all contained the respiratory droplets well except for one (purchased in a foreign country and with the loosest weave). All but one fogged my glasses up. The one that did not fog my glasses was also, by far, the most comfortable. (As an aside, the fabric of my favorite gaiter was buttery soft, had a seemingly tighter weave but was very easy to breathe through, had a cooling effect, and did not slip off of my nose as I ran hard. Some of the other gaiters slipped from time to time but none of the masks tested did.)

In the end, I definitely feel that most masks and gaiters DO contain respiratory droplets (at least the larger ones) and I still disagree with the highly publicized article stating that gaiters are worse than not wearing anything at all. The key, I feel, is to find a mask or gaiter that is comfortable for you so that you will wear it. Since I have to wear glasses when training and racing for my vision, I will choose a comfortable gaiter that does not fog my glasses and that stays put on my nose while running.

This article is really about the process and my personal opinions. I do not endorse any specific products. I only endorse the importance of wearing something while exercising in public. I am happy to supply any of you a list of which mask/gaiter vendors I used for this study upon request.

Please be safe out there while you are training and racing!

Dr Jeff

Dr. Jeff Krebs is a Board Certified Internal Medicine physician specializing in Hospital Medicine. He has practiced in San Diego for over 34 years. As a long-time competitive athlete, he has a special interest in sports medicine.
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