'Hey that was you I saw the other day wasn't it? Monika right?.....'
Go easy on the Fucking compliments women hate guys coming straight out with compliments, it's awkward and creepy. You can show you know her name already that will be enough of a compliment. If she does ask how you know her name. You asked who the girl was who always works out hard.
X1000 you shouldn't compliment her at all. If you're coming up and talking to her basically out of the blue, she already knows you find her attractive.
Treat her like a normal human being.
Guys who compliment typically make me think, "ew you're gross, I'm better than you" No lie, that's my internal dialogue. I'm a bitch.