According to that guidance, people should be wearing a face mask while exercising outside their homes. If open, gyms and fitness centers may require patrons to wear a mask. It’s all with good reason: There’s evidence that your risk of spreading virus particles may be greater during exercise, when you’re breathing heavier, making mask-wearing that much more important. A special report in the April–June 2020 Apunts Sports Medicine performed a new analysis of available data that suggested that when breathing intensifies during exercise (since your body is working harder), the speed and distance you expel respiratory particles that could spread the new coronavirus both increase. Those study authors concluded that keeping more distance between yourself and others while exercising (beyond the six feet that is recommended for the general public) and wearing a mask are potentially really important to help reduce the spread of COVID-19. More research is needed to confirm these findings, however. Note that wearing a face mask may make exercise feel somewhat more challenging because it can slow the flow of air you’re able to breathe in (making your workout potentially feel more intense). They are generally safe for healthy individuals, but if you have a cardiovascular or respiratory condition consider lowering the intensity of your workouts or consulting with your doctor, advises the American Council on Exercise (ACE). And if you feel dizzy, light-headed, or short of breath, slow down or stop exercising until the symptoms go away. Which types of face mask are best for exercising in? If your mask soaks up moisture — from sweat, for instance — it will become less effective at preventing the spread of droplets, says Kathryn Melamed, MD, a pulmonologist at UCLA Health in Santa Monica, California. Plus, it can be pretty uncomfortable to breathe when you’re wearing a heavy, soggy face mask. On the other hand, if your mask is too thin, it might not be effective, she says — “some of the droplets can pass through, particularly if you’re breathing heavily, as during exercise.” Whether you’re shopping among the many brands now selling face masks or DIY-ing it, here’s some advice from Dr. Melamed and others about what to consider. RELATED: 7 Tips for Staying Active During a Pandemic

Make Sure Your Face Mask Fits Well

First of all, when it comes to choosing a face mask for exercise, make sure it’s a good fit, says Matthew Levy, DO, a senior medical officer and an associate professor of emergency medicine at the Johns Hopkins University School of Medicine in Baltimore. “The mask has to fit well, not fall off while doing an activity, and not require frequent adjustments.” In general, the mask should be big enough to cover your nose and mouth, yet also comfortable and snug around your cheeks and nose, according to ACE. “I would recommend people test their masks at home with vigorous movement to ensure they can stay secure without ongoing manipulation or repositioning,” Melamed says. Once it’s on, it should stay put. Some masks have elastic loops that fit over your ears; others tie behind your head. Some masks feature clip attachments that allow you to connect the elastics in the back of your head, keeping the straps off your ears. And a note about bandannas: They’re better than nothing, but if you have a tighter fitting option, go with it. A study comparing different face mask materials published in the journal Physics of Fluids in June 2020, showed that while bandannas do tend to be thicker than other materials (which is generally more protective), they were the least effective option for preventing the spread of droplets. The reason? Bandanna face coverings are too loose, and allow more droplets to leak out. RELATED: Everything You Need to Know About Working Out at Home

When It Comes to Material, Pick Tightly Woven Cottons. More Layers Are Better

Material matters. All cloth face masks — including surgical ones — are breathable to some extent, according to the American Lung Association (ALA), among other sources. (If you have a lung or heart condition that may make breathing in a face mask challenging during exercise, ACE and ALA recommend consulting your doctor.) But if your mask is too breathable (or thin), it may not offer enough protection, especially if you’re breathing heavily (like during high-intensity exercise) or talking loudly, Melamed says. Cloth masks made of at least two layers of fabric will be your best bet, as the multiple layers will help buffer more droplets. “Fabrics such as flannel, muslin, tightly woven cotton, and tea towel fabric have been shown to reduce the transmission of respiratory pathogens,” says Donald Dumford, MD, the medical director for infection prevention at Cleveland Clinic Akron General. According to information from the World Health Organization and Stanford University, polyesters, nylon, rayon, and polypropylene layers can be effective, too. In the same study published in Physics of Fluids, a stitched mask made of quilting cotton (70 threads per inch) was the most effective at preventing the spread of droplets by distance compared with (in order of effectiveness) a commercial cone mask made of randomly assorted fibers (no thread count listed), a folded cotton handkerchief (55 threads per inch), and a bandanna made of elastic T-shirt material (85 threads per inch).

Be Smarter Than Your Mask: You May Have to Carry a Spare, and You Still Need to Take Other Precautions

Donning a face mask doesn’t eliminate your risk of catching COVID-19. You still have to practice smart behaviors. The ACE recommends that if you tend to sweat a lot during exercise, you should carry a second mask with you to swap in mid-workout. Moisture can reduce the mask’s effectiveness. And continue practicing other precautions too, Melamed says. “Masks are meant for use as a strategy to mitigate disease spread, along with other measures such as social distancing, hand-washing, and minimizing face touching.” RELATED: Gyms, Studios, and Fitness Instructors Offering Online Workouts Right Now

Yes, You Can Make Your Own Workout Face Mask

According to the CDC, you can make your own cloth face masks at home to help prevent the spread of COVID-19 during exercise. They even offer tutorials for both sewn and non-sewn options. Simply find your fabric of choice (the CDC recommends quilting fabric or cotton sheets; T-shirt fabric can work, too), some elastic (rubber bands, string, cloth strips, or hair ties are also good options), a pair of scissors, and any sewing materials you may need. Make sure your mask is snug, yet comfortable; completely covers your nose and mouth; stays in place with ties or ear loops; includes at least two layers of fabric; and allows you to breathe without restriction, according to the CDC.

5 Face Masks Designed for Exercise

Are there masks specifically designed to be used for exercise? Yes, a few options are out there, but no studies evaluating or comparing their effectiveness have been done at this time.

1. Adidas Face Covers

These soft, breathable face covers are made of two layers of recycled polyester and elastane. They’re designed for a snug fit — to keep the mask in place while you move — with some stretch in the fabric and elastic ear loops. The masks are machine washable. $16 for a 3-pack; Adidas.com

2. Athleta Made to Move Mask

The women’s athletic brand Athleta offers two-layer fabric masks. The outer layer is made of lightweight polyester spandex, while the inner layer is made of breathable polyester mesh. The masks also feature flexible plastic boning in the center of the mask to keep the fabric out of your mouth, and an encased wire that you can adjust to fit securely over your nose bridge. $25 for a 3-pack; Athleta.com

3. Hanes Wicking Cotton Masks

These soft, reusable masks are made with three layers of moisture-wicking cotton, as well as cotton-covered rubber band ear loops for a soft, snug fit. The adjustable nosepiece and front panel pleats allow you to personalize your coverage. They’re machine washable and meant to be disposed of after 20 uses. $25 for a 10-pack; Champion.com

4. Reebok Face Covers

These masks provide two layers of soft, breathable fabric (93 percent recycled polyester and 7 percent elastane) that you can wash and reuse again and again. Stretchy ear loops and a snug fit keep the masks securely in place while you walk, run, and cycle. Like the other masks on this list, these offer full nose and mouth coverage. $20 for a 3-pack; Reebok.com

5. Puma Face Mask

Nab three layers of protection with these face masks. The combination of nylon and spandex is designed to keep you cool yet covered, while the adjustable straps offer a custom fit. Wash in a garment bag before using, as well as in between uses. A portion of the proceeds from these masks will go toward the UN Foundation’s COVID-19 Solidarity Response Fund for the World Health Organization. $12 for a 2-pack; US.Puma.com