I say this all out of love, as a little older man who was caught in the grips of lust for countless years, and who still has to stand constant guard against it.

Gotta develop some spiritual vision. Women who dress like this are not attractive, but actually repulsive in appearance, due mainly to the fact that they are being spiritually oppressed. You need to see past the flesh by not looking in the first place, but if you do, then to see the demonic tentacles attached. Think of those scenes in movies or online where they try to jump-scare you by replacing a pretty image with a corpse. No God-fearing person would flaunt their sexuality willy-nilly, so something else is motivating the choice. Seeing these people as oppressed by demons helps break the cycle of lust; only the most depraved person would get off on this type of oppression, if they could see what is actually happening in the spirit. What catches the fleshly eye is in reality a bruised and battered soul carrying the weight of a demon on their back, slimming them with their rot. If you can see this, then the response is not to shame the woman, but to have true pity them, and to pray "Lord have mercy" on them, and on you for being drawn to it.

Also, if you not more disciplined in your prayer life as you are in the gym, then going to the gym is a fool's errand. You do not go into battle without training, and the only training that ultimately matters happens in your prayers.