1)   This happened back in August but the report just came out today: 

https://news.yahoo.com/chicago-gym-saw-dozens-covid-160915404.html?guccounter=1&guce_referrer=aHR0cHM6Ly93d3cuYmluZy5jb20v&guce_referrer_sig=AQAAAKFI4TZbch-4T9BbP5Ik6b0s06VQtfhZ2ZKzEkZbT8M90FjK0vbtrRo8BuleuwmyBgU-BoOaorqaMbp5icJlPEg5Y3T4tY9l3Lrw0Rr6tbdAaDNPl_APhmJHA_wgWPyyOg2KjIYfvCrt3V7vt1XfSq_IrMht3Uq-qicR3hsihr-F - A Chicago gym saw dozens of COVID-19 cases after infected people attended HIIT classes without masks (yahoo.com)

In one week in August, 55 who attended exercise classes at a Chicago gym contracted COVID-19.

Less than a quarter of gym-goers wore masks during their workouts, and almost none socially distanced.

The gym had precautions like temperature checks, but some people went to class with symptoms anyway.

[snip]

Still, 22 people who attended had symptoms the same day they went to work out, including fever, cough, headaches, and loss of smell and taste.

Three people went to class who tested positive for COVID-19 that day or before.

2)  Another gym transmission this time by an instructor who taught two fitness classes at two different gyms, the instuctor also passed on Covid to another fitness instructor who taught a class at the third facility and passed on Covid to that class! The second instructor was a 46 year old male who ended up in the ICU.

This happened in Jun-July, report released today: (the full report is very interesting regarding mask usage and non mask usage and who was infected)

https://www.cdc.gov/mmwr/volumes/70/wr/mm7009e1.htm - Community Transmission of SARS-CoV-2 at Three Fitness Facilities — Hawaii, June–July 2020 | MMWR (cdc.gov)

Twenty-one COVID-19 cases were linked to an index case in a fitness instructor.

An interesting tidbit in report:

4 hours before symptom onset, instructor A taught a 1-hour stationary cycling class with 10 participants at facility All 10 participants received positive SARS-CoV-2 RT-PCR test

Stupid, selfish @$$e$!