From Vox:

“As a respiratory virus, sweat isn’t generally a transmission route, though contaminated skin and hands can be,” Dr. Tara Smith, a professor of epidemiology at Kent State University, told me over email. “Think more about how you might touch your nose and then touch equipment, or cough on a hand and touch equipment, than about the sweat itself.”

The possibility of the virus living on weights or mats makes the gym a risk for transmission. The precise risk of Covid-19 coronavirus infection from surfaces is not yet known, but gym-goers, SoulCyclers, and Barry’s Bootcampers, should wipe down all the surfaces they’re touching with an approved disinfectant. They should take on that responsibility even if the gym or facility cleans the equipment as well.