I've been noticing a bunch of cute girls at my local gym but I have no idea how to approach without looking like a creep.

I've smiled at a few and they smile back which is an IOI but i never follow up on it.

What can I do, what are some options and what ways can i approach a girl whos 1) running, 2) doing light weights, 3) doing ab workouts, etc.

"You look tired. I think you've earned a break. Let's get in the tub"

"Are you training for when you have to run away from all those creepy guys who try to hit once you get outside?"

"Nice yoga pants. Whoever invented those deserves a raise"

Them smiling at you back it's not an IOI. It's a forced IOI and girls would generally do this if they are friendly or in a good mood or for the sake of it.

How I'd approach the situation is I'd go somewhere where she can spot me. And offer to help her with and exercise or aks her to explain to you what is she doing and what muscles it works out. If you can't do that you need inner game problems.

So just go indirect(gay style) and whatever music it's on. Ask the girl:
"Quick question. Do you think this singer is sexy/cute? I'm asking because my 7 year old niece has a poster on her wall and I dunno what to think."

The best way to approach a woman at the gym is to do it after you get a good muscle pump...

The fear of being seen as a creep is just a limiting belief. You can approach a girl on a tread mill if you want, however this takes a little more confidence. The easy thing is to approach a girl lifting weights or a girl after she has finished working out.

I'm now to gym pickups but I'm thinking I'm just going to ask her for a spot, and talk between rounds

If i wanna aproach a girl in the gym, i pas her and say somthing nice and walk away. If i see the girl the next time, i smile, and maybe we start to talk.

Important is, that the girl start the contact, i give her the feeling, that she controlls the situation.

My most recent ex-gf was from a gym interaction.
Basically, first time i saw her I asked her name, that's it. Nothing else. Just walked away.
Second time I saw her at the gym, she approached me, I did not give her much attention. I just continued with my work out. Had a small talk convo of about 5 mins.
Third time I approached her, asked her if she wanted to go to a party with me (It was 8 pm on a friday night). She said yea. Both left together to the party, woke up together in my friends bed. She was on her period so nothing actually happened. But it opened the door to a relationship.
Yours doesn't have to be this way, but ill tell you, in a gym situation, girls expect all the meat head fag guys to be all over them. So just show small interest, give her space, then ask her out to a date somewhere else. You don't want to establish rapport in a gym setting. My personal opinion.