The Centers for Disease Control and Prevention are urging people to stop ignoring face covering and social distancing rules when they hit the gym after two new studies confirmed they are strong spreader locations.
The agency released findings Wednesday on research it undertook at gyms located in Chicago and Hawaii that saw a high "attack rate" associated with outbreaks last summer.
In Hawaii, 21 people contracted the virus in July from a cycling fitness instructor who had the disease and taught classes for three days. In the Chicago location, 55 out of 81 people who attended high-intensity fitness classes during the last week of August contracted COVID-19, the studies said.
The common factor in both outbreaks was the lack of mask use, according to the CDC report.
The Hawaii cycling class did not mandate mask use among its patrons, while gym users in Chicago rarely used face coverings, according to the report.
"Among 58 exercise class attendees who provided information on in-class behaviors, 44 (76%) reported infrequent mask use, including 32 of 38 (84%) attendees with COVID-19 and 12 of 20 (60%) without COVID-19," the report on the Chicago outbreak said.
The report added that the Hawaii cycling facility kept its doors and windows closed during the classes with the infected instructor, increasing the chances of transmission.
Two people were hospitalized in the Hawaii outbreak and one in Chicago, according to the report. Two of the Chicago patients visited the emergency room with COVID-19 symptoms, according to the CDC.
There were no reported deaths linked to the outbreaks, the CDC reports said.
The agency urged gym facilities to make sure they have proper ventilation standards, decrease capacity and enforce mask-wearing and social distancing rules among its patrons to prevent future incidents. If possible, patrons should stick to outdoor gym activities, the CDC said.
"This outbreak reinforces the need for combined COVID-19 prevention strategies, including universal mask use in public settings when persons are with others who do not live in the same household, especially indoors," the CDC said in its Chicago report.