Before you head back to your fitness class during the coronavirus pandemic, heed the word of researchers in South Korea who say that vigorous exercise in confined spaces should be minimized during outbreaks.
Their research, published May 15 in Emerging Infectious Diseases, revealed that during 24 days in Cheonan, South Korea, 112 people were infected with Covid-19. They were all associated with fitness dance classes at 12 sports facilities.
Contact tracing pinpointed a nationwide fitness dance instructor workshop on February 15 in Cheonan, where 27 instructors, all asymptomatic, trained intensely for 4 hours. They went on to teach their own classes, unaware that some of them were infected.
By March 9, researchers identified 112 Covid-19 cases associated with fitness dance classes in 12 different sports facilities. At the time of confirmation 82 (73.2%) had symptoms, with 30 (26.8%) remaining asymptomatic. On average students developed symptoms 3 1/2 days after participating in a fitness class.
Researchers break down the transmission rate:
· 50.9% of cases involved transmission from instructors to students during classes, which lasted 50 minutes twice a week
· 33.9% were in-family transmission from instructors and students
· 15.2% were from transmission during meetings with co-workers or acquaintances.
Among the 54 fitness class students who tested positive for Covid-19, all were women with a median age of 42. Ten of them (18.5%) had preexisting conditions. Cough presented as the most common symptom with about a third of them developing pneumonia. Recovery time ranged from 13-66 days after symptom onset.
Researchers point to large class sizes, small spaces, and intensity of the workouts as reasons for the rapid spread. The report says, “The moist, warm atmosphere in a sports facility coupled with turbulent air flow generated by intense physical exercise can cause more dense transmission of isolated droplets.”
Classes with less than five participants in the small space did not yield any known transmission.
They also note that no one tested positive for Covid-19 who took Pilates and yoga (7-8 students) in one of the same facilities. Researchers believe that’s due to the lower intensity of the workouts.
Lead researcher, Dr. Subkin Jang, clinical assistant professor in the Division of Infectious Diseases, Department of Medicine, Dankook University Hospital, concludes in the report, “Because of the increased possibility of infection through droplets, vigorous exercise in closely confined spaces should be avoided during the current outbreak, as should public gatherings, even in small groups.’
Source : Forbes