I think I pulled a muscle in my arm while putting on a sports bra. I didn’t even pull it at the gym. I pulled it at home, getting ready to go to the gym. It really hurts! But lest you think I’m lame for injuring myself while trying to put on proper gym clothes, in my defense, those suckers can be really hard to put on!
For more information, please see this instructive article on how to put on a sports bra.