CDC: 55 COVID-19 cases identified among 81 fitness class attendees at Chicago exercise facility

The CDC said 55 COVID-19 cases were identified among 81 attendees of indoor high-intensity classes at a Chicago exercise facility in August and September.

The CDC just recently released this report.

On Sept. 8, 2020, the Chicago Department of Public Health was notified of a potential outbreak of COVID-19 at the exercise facility.

From Aug. 24 to Sept.1, 2020, the facility offered four to eight high-intensity indoor classes daily. Officials said mask use, temperature checks and symptom screenings were required on entry; however, patrons were allowed to remove masks during exercise.

They also brought their own mats and were stationed at least six feet apart.


A patron notified the facility on Sept. 1 of a positive COVID-19 test. The patron last attended class on Aug. 28.

The facility then closed for 13 days and informed attendees of the possible COVID-19 exposure. On Sept. 8, CDPH said they identified a cluster of cases linked to the facility.

What we know about the outbreak:

  • COVID-19 cases were identified among 55 of 81 attendees of in-person classes held during August 24–September 1, 2020;
  • 49 cases were confirmed by RT-PCR testing and six probable cases among attendees who had compatible symptoms but negative or no RT-PCR test results;
  • 43 attendees with COVID-19 participated in multiple classes while potentially infectious;
  • 22 attendees with COVID-19 attended an exercise class on or after the date of symptom onset, including three who attended on the same day or after they received the positive test result;
  • Among 58 exercise class attendees who provided information on in-class behaviors, 44 reported infrequent mask use, including 32 of 38 attendees with COVID-19 and 12 of 20 without COVID-19; 
  • Among 91 facility attendees (88 patrons and three employees), 10 had neither testing nor interview data available and were excluded;
  • 68 attendees were Chicago residents, 71 attendees were women;
  • Among 73 interviewees, 24 reported medical conditions associated with severe COVID-19 illness;
  • Attendees with COVID-19 reported participating in a median of five exercise classes, attendees without COVID-19 reported attending a median of three exercise classes;
  • 12 attendees with COVID-19 and eight who did not have COVID-19 reported social exposures outside the exercise facility;
  • No deaths were reported.

The CDC recommends facilities improve ventilation, enforce consistent and correct mask use and physical distancing, remind infected employees and patrons to stay home and away from others and increase opportunities for hand hygiene.


Additionally, the CDC says conducting exercise activities entirely outdoors or virtually could further reduce transmission risk.

The full report from the CDC can be found here