Approaching at the gym

I’ve recently been seeing this girl I know at the gym. One of my closer friends has been with her younger sister for a long time now and we’ve met one time years ago over drinks with all of us (I was not single). I liked her and I’m definitely attracted to her (per page rules I’m a man and we’re both mid-twenties). I want to talk to her, but the only time I see her is when she’s on the elliptical with her headphones on. She’s there before me and she just uses the machine the whole time and leaves. I’m really nervous about approaching women I’m attracted to ( my only girlfriend was a friend before we dated so there was really no approach or starting from 0) and this particular situation makes it so much harder. My friend is really of no help in setting us up and I’m not going to push him. I really think we would be a good match, or I at least really want to find out. I live in a small city (nearly a town) and finding genuinely good people whom I’m also attracted to and are single is hard to find, so I don’t want to ruin my chances with a bad first impression like interrupting a workout to attempt to flirt. I never see her anywhere else but the gym, but I do know from friends that she works at a local restaurant. What’s my move here?