No gyms. No yoga studios. No Orangetheory. No spin classes. No rock walls.

But there’s still this, which doesn’t require even Zoom video conferencing: a pair of running shoes and an expanse of open road or trail.

For those of us who’ve long thought the easiest and most efficient cardio workout was lacing up our shoes and going out the door for a run, we have a lot of company. People who haven’t run in ages, or ever, are pounding the pavement.

And it’s making some people nervous. You can see the complaints on social media. About runners coming too close. About them breathing too hard. About crowded sidewalks and a lack of social distancing.

“A woman started screaming at me the other day,” said Kate Hoare, the communications director for the Golden Gate Running Club, who was running near Nob Hill with her fiance. “She was screaming, ‘6 feet, 6 feet.’ We weren’t near her, but we were near each other. My fiance had to tell her that we actually live together.”

Runners do breathe heavily. They occasionally spit. They are moving faster than walkers.

But are they a danger to society?

“It is difficult to imagine that joggers represent a threat to others,” wrote John Swartzberg, an infectious disease expert and professor at UC Berkeley’s School of Public Health, in an email. “We define a significant exposure to SARS CoV2 (the virus that causes COVID-19) to be face-to-face contact within 6 feet with someone with a symptomatic infection that is sustained for at least a few minutes (e.g. 10 minutes).

“The chance of catching SARS CoV2 from a passing individual in a public space in negligible.”

Still, tensions are running high. Nerves are frayed. So, just like everyone else, runners should be mindful of their impact. And follow some basic etiquette rules:

• Maintain 6 feet of separation. “Give everyone a wide berth,” said David Leipsic, the president of Tamalpa, the oldest running club in Marin County with 700 active members.

• Go out at less popular times and in relatively uncrowded areas. “We’ve been changing up the times we run, and where we go,” Hoare said. “Hills seem to be less popular. Some side streets are less traveled.”

• Keep the headphones off. Hoare was biking when an oblivious runner — in an effort to give oncoming walkers room on the sidewalk — jumped into the road right in front of her.

• Give others warning. Rather than come right up behind someone, call out to let that person know you’re about to pass.

• Don’t crowd the sidewalk. Reduced traffic means runners are using the street and leaving the sidewalk to walkers. But keep your head on a swivel. “I just urge everyone to be mindful,” Hoare said.

• Watch out for poison oak. On trails, runners are being good about standing aside to let others pass but might pay the price with poison oak. Hoare and her fiance carry wipes for just such occurrences.

• Be mindful of other hazards. “I’m avoiding public water fountains,” Leipsic said.

• Masks? Not necessary but not impossible. Leipsic has seen some runners in masks and wore one himself during the smoke-filled days during the wildfires. “It’s not too bad, just a little sticky and wet,” he said.

• Be polite: A smile or a hand raised in greeting goes a long way during these anxious times.

• And a no-brainer: Don’t spit if you’re near anyone.

The need for courtesy extends to everyone. Walkers shouldn’t be taking up the sidewalk, walking three abreast even if they all live in the same home. Bikers should slow down. Leipsic said the only uncomfortable confrontation he has had while running was when two mountain bikers came flying down a single-track trail on Mount Tamalpais that they weren’t supposed to be on and almost hit him.

Runners, like everyone else, are out there trying to keep healthy and sane.

“Regular exercise is an effective stress management tool,” writes Randall Stafford, a professor of medicine at Stanford, on Scope, a blog by the School of Medicine. “Maintaining or improving your fitness level can also reduce the risk of viral infection and even the chances of severe COVID-19 complications.”

Hoare, who works in asset management for Wells Fargo, is sharing at-home workouts with other Golden Gate club members on their dedicated Slack channel and doing Zoom challenges: 100 push-ups and then drink a beer, 15 minutes of planking and then drink a beer. She started running in 2016, after shoulder reconstruction surgery forced her to give up basketball.

Leipsic, a middle-school teacher in Marin, started running in high school in Marin County, and ran cross country at UC Santa Barbara. He has run the grueling Dipsea race — from Mill Valley over Mt. Tam to Stinson Beach — for 28 straight years. His streak will end in June, as the race is canceled.

He gave out some tips on running during the time of coronavirus in Tamalpa’s monthly April newsletter. He wrote, “I really believe that running is the best, and healthiest form of exercise we can be doing right now. It strengthens our cardiovascular system, keeps our weight in check, and boosts our overall happiness and well-being.”

Leipsic thinks this pandemic could create a new running boom.

“It’s the best workout,” he said. “You can do it anywhere. All you need is a pair of shoes,”

“And,” added Hoare, “a really good sports bra.”

Just please be mindful.

Ann Killion is a columnist for The San Francisco Chronicle. Email: akillion@sfchronicle.com Twitter: @annkillion