Not at all surprising: Indoor fitness classes are a bad idea

[Snorlax94]

Even worse — a 4 hour indoor workout for fitness instructors in February, which led to the instructors returning to their home gyms to lead classes.

https://wwwnc.cdc.gov/eid/article/26/8/20-0633_article

[BostonCard]

Not sure about this conclusion:

Vigorous exercise in confined spaces should be minimized during outbreaks.

I know what they meant.  But confined spaces are fine if you are by yourself.  They're just problematic if you are in a class with 30 other people (especially if one is infectious).

BC

[Snorlax94]

F

Not sure about this conclusion:

Vigorous exercise in confined spaces should be minimized during outbreaks.

I know what they meant.  But confined spaces are fine if you are by yourself.  They're just problematic if you are in a class with 30 other people (especially if one is infectious).

BC

The most two interesting nuggets for me:
“Before sports facilities were closed, a total of 217 students were exposed in 12 facilities, an attack rate of 26.3% (95% CI 20.9%–32.5%) (Appendix Table 2). Including family and coworkers, transmissions from the instructors accounted for 63 cases (Appendix Figure 2). We followed up on 830 close contacts of fitness instructors and students and identified 34 cases of COVID-19, translating to a secondary attack rate of 4.10% (95% CI 2.95%–5.67%). We identified 418 close contacts of 34 tertiary transmissions before the quarantine and confirmed 10 quaternary cases from the tertiary cases, translating to a tertiary attack rate of 2.39% (95% CI 1.30%–4.35%).”

They followed up and traced secondary, tertiary and quartenary contacts and the total from all of those (including household contacts) was about the same as the total infected from the fitness classes. It reflects how much superspreading events can dominate (though, the downstream infections were reduced because of all the contact tracing). But still, this makes me wonder how social big bars can reopen. If an infectious person club crawls and hits multiple bars a night for each night of the weekend, it makes me feel     no place in the US would be able to contain it and it would lead to another SIP.

The second nugget, not really surprising, and very anecdotal:
“Of note, instructor C taught Pilates and yoga for classes of 7–8 students in the same facility at the same time as instructor B (Figure; Appendix Table 2), but none of her students tested positive for the virus. We hypothesize that the lower intensity of Pilates and yoga did not cause the same transmission effects as those of the more intense fitness dance classes.”

[BostonCard]

That is the most likely conclusion, though it also could have been that the instructor was less infectious at the time he or she taught her class than the index case.  That's the challenge with n of 1 cases, there's always a "just so" story that accounts for the observation.  That being said, I have no reason to doubt that the intense aerobic exercise was a factor in the superspreading event.

BC

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As an aside, over my lunch I participated in an indoor fitness class (by zoom, of course).  The "new normal", I guess.

BC

[magnus]

Here's a positive news event for gyms and covid.

https://www.cnn.com/2020/11/19/us/gym-ve...index.html

Trainer came down with Covid in September and exposed 50 athletes.  None of the athletes contracted the virus likely due to the ventilation and spacing precautions that the the gym took.

[M T]

This report of problems in an indoor workout place was earlier, but it seems we are now getting a smorgasbord of news stories and even studies.  What ever you are inclined to believe, there is a report supporting that idea.