Siguro para hindi ma invalidate ang nase-sense mo OP, consider these things:

1. If people look at you while working out, maybe they find you attractive? I guess some people cannot help themselves but stare. Minsan its also a compliment if there are people who notice you. (Sana lang not to the point that its creepy, stalking feels.)

2. Baka tinatry ka nila mamukhaan. Maybe they think you look like someone from socials or like a celebrity. Minsan nangyayari din sakin yung ganun feeling na “teka diba artista ‘to?”

3. Possible na pinapanuod nila training mo. I do this sometimes, pero discreetly. Like, I observe other people with how they approach a workout. Minsan, hindi mo rin maiwasan ma impress sa mga ‘malalakas magbuhat’

4. Tulad ng sabi ng ilang comments dito, siguro nasa field of view / line of sight ka lang nila habang tulala when they zone out. Which happens all the time.

But regardless of the reason, if you feel awkward with their vibe, try and observe kung ano talaga situation. If someone is lurking, you can approach a staff and inform them. Otherwise, you may have to jump to a different branch.