As the arrival of spring has brought warmer and sunnier weather to Vancouver, runners have once again taken to the seawall, but experts warn the narrow path could be the perfect transmission zone for COVID-19.

Doctors say that while running is a great way to stay healthy and prevent illness, the activity itself can increase the chances of producing micro-droplets that can transmit the virus from person to person, if they're too close.

"I have run 58 marathons and I know how it is running with buddies," said David Nieman, a professor of health and exercise science at Appalachian State University in North Carolina.

"Everybody is breathing heavy and spitting and snorting and clearing their throat."

But Nieman says that doesn't mean you should give up exercise altogether.

Staying active still key to staying healthy

According to Nieman, over three decades of research shows that daily physical activity increases the circulation of immune cells throughout the body which can better detect and destroy invading viruses.

"I highly recommend that physical activity be included as a part of their lifestyle right now as people do everything possible to keep their immune system in good shape during this pandemic."

The only exception, he says, is if people start to feel ill. "People think they can sweat it out by going for a hard run or bike ride and that's a very dangerous strategy."

He says studies on animals have shown that exercise during illness can increase mortality rate or increase the severity and duration of the illness.

Nieman says it's important to weigh the benefit of regular exercise against the risk of getting sick or spreading the virus.

"We have to balance all of that and make sure that the benefit of activity on the immune system Is not in any way outweighed by the risk that's involved if the crowds get too thick."

A man runs along the seawall in Stanley Park in Vancouver, British Columbia on Thursday, March 26, 2020. (Ben Nelms/CBC)

Jen Segger, an endurance coach in Vancouver, says there are ways people can stay active while keeping their immune system in good shape.

"They may have to adjust things like volume and intensity so maybe you're shortening your runs or maybe you're taking really good care after a hard interval session… making sure you're eating really good food."

Many national and provincial parks have already been closed in B.C. as well as popular hikes like the Chief in Squamish. Segger thinks that's contributing to clustering in the high-traffic trails that have stayed open, despite orders requiring physical distancing, or staying two metres away from anyone not in your household.

Tips for safe running during a pandemic

Dr. Lawrence Loh, interim medical officer of health at the region of Peel in Ontario, says now is the time to embrace running alone.

He says for people who don't have symptoms, the safest way to get some exercise while enjoying the outdoors is to stick to less popular areas close to home.

"Traffic volumes tend to be light so it's easy for me to dart off the sidewalk onto the street if I need to make sure I'm maintaining that critical two-metre separation between me and other people who might be walking about."

Running earlier in the morning or later in the evening can also help avoid the crowds, Loh says.

For those that want to go the extra mile, Nieman recommends buying running scarves online that help prevent micro-droplets from leaving your mouth.

If you have a COVID-19-related story we should pursue that affects British Columbians, please email us at impact@cbc.ca.