I wear them nearly every time I go to the gym. Most of my gym pants are sweats. The exceptions are the polyester track pants that everybody else has. I'm sure you've seen similar... anyway, because i so value my privacy, I refrain from posting pictures of myself online. Thus, I will not be posting pictures of me in sweats.
Or have an old iPad. They're never flipped 90 degrees, but they transmit upside down about 10 percent of the time, and it's never clear before posting/sending that it's going to happen.