coronavirus

Exercise and Coronavirus: ‘Slipstream' of Droplets Possible Around Runners, Study Suggests

Guidance includes exercising during non-peak hours, choosing quieter streets in your own neighborhood, and switching to the other side of the street when you can’t pass without encroaching on the 6-foot rule

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Exercising has never been more important for both physical and mental health, which is why doctors and elected officials are now warning people to think twice about where they seek fresh air amid the nationwide "stay at home" order.

San Diego’s turn towards sunnier weather will only increase the amount of people walking, running, and cycling on neighborhood streets, which could increase the likelihood of airborne transmission should you pass an unsuspecting carrier at the wrong moment.

“There is some data to suggest that the spread could become worse, or more significant, in the setting of heavier breathing,” said Dr. Paul Schalch Lepe, a San Diego surgeon who specializes in ear, nose, and throat conditions.

Lepe says it’s unknown how long the virus particles can live in the air but he wants people to take extra precautions while exercising.

“If we were to add color to particles when someone coughs or sneezes, it would be very impressive. It really looks like a cloud. You don’t want to run straight into that,” said Lepe.

The problem, of course, is when people are running with earphones they may not hear someone cough and they’re traveling faster, which increases the likelihood of running into a cloud of droplets before they drop to the ground.

San Diegans walking and running through North Park said it can often feel like an urban obstacle course with so many people trying to exercise all while trying to avoid each other.

“You have to be aware of your surroundings," said Kelly Bryant who tries to walk down the middle of streets when possible to give herself plenty of room. "It’s just like the 405 in traffic, you have to see what everyone else is doing and navigate around.”

Bryant admits to holding her breath when passing other people, not knowing if it actually works.

Public Health guidance includes exercising during non-peak hours, choosing quieter streets in your own neighborhood, and switching to the other side of the street when you can’t pass without encroaching on the 6-foot rule.

But a new 12-page study out of the Netherlands found six feet may not be enough of a bubble when exercising. According to the study, which looked at how air flows around a body in motion, the exhalation from a runner can create a “slipstream” of droplets behind them for much more than six feet.

The study’s authors found people who run directly behind another runner are significantly at more risk of breathing in the droplets than someone who is running next to them or staggered behind them.

Doctors say face coverings are an important tool in slowing the spread of the coronavirus because they can help keep asymptomatic carriers from spreading it.

But the idea of wearing masks while exercising, as opposed to shopping for groceries, has been a tough sell for many San Diegans.

“Me as a runner, I can’t have something over my mouth because I’m breathing in extra oxygen, so it doesn’t make sense,” said Jim Vrakas, who lives in North Park.

When asked about the county’s suggested guidelines for people exercising, San Diego County Communications Director Michael Workman said bluntly “If you leave your place, cover your face,” that’s our guidance.

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