So I've been grinding online exclusively for 5 years, 50-200nl stakes mainly, and I'd constantly feel the need to study because the competition was so tough. Recently I switched to live poker. Mainly 2/5 (have a small sample at some 5/10 as well), a lot of these are in backroom games where the players are even worse than at the casinos, and I honestly feel that after a now 500-hour sample size there's really no player who is giving me a run for my money.

Due to this I guess I sub-consciously don't have that urge to study as I did when I was grinding online vs other solid players who would out-think me in some spots.

I'm now thinking of getting back into online to grind some harder games like 50z (knowing that my ev is probably much lower in those games) just to stay sharp.

My question being, is this a reasonable solution to this issue or do you think its possible to be really good and stay sharp playing live 2/5 and studying on the side?

The problem is strictly a financial one as live requires a much much higher bankroll than online. As you move up in live you will find challenging opponents that require you to stay sharp, imo that starts at 5/10 (especially if 5/10 is the biggest game available) and increases as you play bigger; I agree there are no challenging opponents that play live 2/5 for a living.

Yes a good strategy to stay sharp could be to play online a little; but really it's the off the table studying that produces the best results (which doesn't require any online play), in my own experience.

Try to stay cognizant of when and why you are taking exploitative deviations at live 2/5 and what the equilibrium spot might look like. This should keep your game relatively sharp.

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Play 20/40 nlh live at Commerce (LA) or Bellagio (Vegas). You will find plenty of tough players. You will not have any trouble staying sharp.

I found myself getting complacent only playing live 5/10 and some 10/25. I only really felt I was improving when I started doing a hybrid of both. Online will def help polish your game and make you theoretically better. When I'm getting a lot of reps in online the spots live vs competent villians are much easier to deal with. In my opinion 2/5 online (NL500) is similar to 10/25 live in terms of skill level.

You can stay sharp playing at any level, but it may be easier at higher levels because it forces you to try harder (or you go broke). Like Jarretman said, off-table study is far more impactful when it comes to improving your game. The only thing about lower stakes is that you can play sloppy and still win, so if you don't do the studying, that sloppiness will become cemented into your game. If you're always studying, you'll become aware of those things and either correct them, or keep doing it because you've studied and know that the strategy is an appropriate adjustment to your stakes (e.g. not bluffing as much at lower stakes).

The key to this game is a solid thought process and true understanding. Those things are partially acquired through playing, but a lot of it is from studying a variety of common spots. Playing tougher games won't necessarily make you aware of your mistakes. You can play 25/50 all day and just tell yourself you played well at the end, and learn nothing. You have to be obsessively self critical to improve.