Is it safe to return to the gym? As a growing number of communities ease the stay-at-home mandates they had put in place to mitigate the spread of the novel coronavirus, gyms are beginning to reopen their doors — even as the virus continues to infect thousands more every day.

To find out more about gyms and the risks for coronavirus exposure there, I spoke with clinicians, researchers, engineers and a gym owner in Atlanta whose newly reopened facility caters, in part, to scientists from the nearby Centers for Disease Control and Prevention. What follows is their expert consensus about whether, when and how best to head back safely to weight rooms, cardio machines and classes, including tips about which gym wipes are effective, what equipment is most grimy, how to socially distance on treadmills and why we should keep several clean gym towels draped over our shoulders throughout our workouts.

By their very nature, athletic facilities like gyms tend to be germy. In a study published earlier this year, researchers found drug-resistant bacteria, flu virus and other pathogens on about 25 percent of the surfaces they tested in four different athletic training facilities.

“When you have a relatively high density of people exercising and sweating in a contained space, you have conditions where communicable diseases can spread easily,” says Dr. James Voos, the chairman of orthopedic surgery at University Hospitals Cleveland Medical Center, head team physician for the Cleveland Browns and senior author of the study.

Gym equipment also can be devilishly difficult to sanitize. Dumbbells and kettle bells, for instance, “are high-touch metal, with strange shapes and many different places people can grasp,” says Dr. Deverick Anderson, a professor of medicine and director of the Duke Center for Antimicrobial Stewardship and Infection Prevention at Duke University Medical Center in Durham, N.C. His group consults with the National Football League and other sports teams about infection control. “They are not easy to clean.”

In consequence, “people are going to have to understand and accept that there will be some risk” of virus transmission, if and when they revisit their gyms, Dr. Anderson says.

“But,” he says, “there are many steps people can take to mitigate those risks.”

First, and most essential, the experts agree, plan to disinfect yourself and any surfaces that you touch at your gym, frequently.

“There should be a sink with soap so you can wash your hands, or a hand-sanitizer station as soon as you walk in the door,” says Radford Slough, the owner of Urban Body Fitness, a gym in downtown Atlanta frequented by doctors and C.D.C. scientists. Sign-in procedures should not require touch, and gym employees should stand behind sneeze guards or be wearing face masks, he adds.

The gym space itself should be plentifully stocked with spray bottles containing disinfectant that meets Environmental Protection Agency standards against coronavirus, as well as clean cloths or bleach wipes for sanitizing surfaces. The standard all-purpose wet wipes that many gyms stock are not E.P.A.-approved, Dr. Voos says, and “will not kill most germs.” Bring your own water bottle to avoid using drinking fountains.

When spraying a disinfectant, give it time — a minute or so — to kill germs before wiping. And clean any grime or dust off surfaces first.

Ideally, other gym patrons who have lifted weights or perspired on machines will have scrupulously scrubbed them afterward. But do not depend on the cleanliness of strangers, Dr. Anderson says. Instead, disinfect any weights, bars, benches and machine rails or knobs yourself before and after every use.

It would be advisable, too, to carry several clean towels, he says. “I would keep one on my left shoulder to wipe sweat from my hands and face, so I am not touching my face all the time, and the other to cover the weight bench” or yoga mat.

Social distancing is also necessary. Mr. Slough says to reduce density, his gym currently allows only 30 people an hour into its 14,000-square-foot facility. Colored tape on the floor boxes off spaces wide enough to keep weight trainers at least six feet apart on either side.

Treadmills, elliptical machines and stationary bicycles also can be moved apart, or some can be taped off or removed from service, Dr. Anderson says.

But appropriate distancing during indoor aerobic exercise remains problematic, says Bert Blocken, a professor of civil engineering at Eindhoven University of Technology in the Netherlands and KU Leuven in Belgium. Dr. Blocken, who studies airflow in buildings and around bodies, says exercisers breathe heavily and produce many respiratory droplets, and with no wind or forward momentum to shift and disperse these droplets, they could linger and drop inside the facility.

“Therefore,” he says, “it is very important to have a well-ventilated gym,” preferably using a system that constantly refreshes inside air with filtered air from outside. If your gym does not have such a system, expect, at minimum, “peak natural ventilation” — meaning wide-open windows on opposite walls — to help move air from inside out, he says.

Finally, to help these various safety measures take hold, gyms should sprinkle their space with posters and other reminders of why and how to sanitize, Dr. Voos says. In his study of microbes and infection control at athletic facilities, germs became somewhat less prevalent when the researchers set out cleaning supplies for trainers and athletes. But the prevalence of germs fell almost to zero when they began regularly educating the facilities’ users about how and why to clean their hands and surfaces.

Still, the decision about whether to return to our gyms as soon as they open likely will remain knotty and personal, dependent to some extent on how each of us balances the benefits of exercise, risks of infection and any health fragilities among those we live with and would return to after working out.

There also may be flash points, including about masks. Dr. Anderson predicts that “few people will wear them” while working out inside, though gyms may require them. He also notes they would rapidly dampen during exercise, reducing their antimicrobial benefits.

“What it comes down to is that the risks will never be zero,” Dr. Anderson says. But at the same time, “there are so many mental and physical health benefits” to the workouts. “So, my approach is that I will accept some risk but be aware of the steps I need to take to mitigate it. And then, yes, I will go back.”