I have no problem potentially offending people in person by running shirtless, but I’m not fool enough to post my photo online to potentially get ridiculed by strangers around the world. As we all know, that has become a popular amusement around the globe.
I can’t think of one outdoor running road race open to the public that I’ve done in the past 40+ years where there was a requirement for a male to cover his torso.
Of course, I always wore a singlet when competing in HS meets. I’m writing about your local 5K, half marathon or marathon.