Hey mate I'm not a personal trainer, but I box and I'm one of the seniors at my gym someone that ppl look up to, and I've dated girls from the gym before. I'm a really social outgoing person I made myself a figure at the gym that ppl want to get to know as well as someone that ppl feel comfortable coming to if they have a problem or need help. So far I've dated 3 girls from my gym all went well I'm not dating any of them anymopre, but there's no awkward feelings between any of us I still talk to all of them regularly.
If you have rapport like that with the ppl at the gym, and a reputation dating girls from the gym won't be a problem for you. I personally reccomend you check out the article players guide to picking up women at the gym
www.wayoftheplayer.com.
Ppl say the gym is a tricky place to pick up women I agree to a certain extent, but if you put the work in like a described above picking up women at the gym is no different then any other place.
Hope that helps good luck mate!!