What do you mean - you don't have 30 mins per day to go walk / jog? Does it not worry you that you may never able to actually retire and have bad physical health on top?
30 minutes isn't much contiguous time and would probably be a net-negative in my goals, even when considering health benefits. It does worry me that I may retire in bad health but I'm saving as fast as I can to avoid that. I'm also speed-running to ensure I will have the time I need to help my parents as they get older. In any case, I am confident I will be able to retire (I nearly have the funds).
To be clear, I'm definitely burnt out. At this point I don't see any way out besides ER. There just aren't jobs out there that use my skills without demanding 30-70 hour weeks.
I'm just saying you can start with a small amount of time, not sure why you think you need more. It will compound and the benefits surely wont be a net negative, especially if mentally burned out. It's much easier to start now than when you're older. To each their own though.
It seems like every time I want to get away for some period I am called back. My bosses work mornings and evenings so they're seemingly always around needing something. And if I don't take care of things right away they just push tasks I'm working on, so my task list never shrinks, only grows.
It's definitely a bad situation but every job I've had ends up like this so I dunno, feels like my only option is to get out ASAP. (And FWIW I'm well in to middle age.)