I live on 3 acres with my 'backyard' being 90 acres of farmland. NO sidewalks. No fence. Not a neighborhood whatsoever. Jackson would never survive if we just stayed here at home all day, lol. I sacrifice a lot to get him the exercise he
needs, lol.
First, I found a nice neighborhood with sidewalks about 5 mins. up the road. So I drive, park my car, and we walk for 35-45 minutes or more. It can be a pain but it's often necessary; change of scenery, new smells, sidewalks to walk on, etc.
We do about 2 dog park visits per week. There's a dog park about 10-15 minutes down the road where he can run free and there's another really nice dog park 20-25 minutes away we go to every Saturday. He's also currently in agility classes every Saturday and we're on week 4 out of 8.
I bring him to my dads house (45 mins away) once or twice per week to run around in his fenced in backyard with his dogs, etc.
Sometimes I will just put him in the car and run some errands, bank, and things like that, as he loves to smell out the window. And we'll go to Petsmart, Petco, etc, as much as possible -- usually once a week. He loves to walk around the stores.
If it's just a lazy day, he's also content to just stay home and inside. So it's not like he has to be constant go go go but I think he's okay with that because of the exercise he gets during the week... so missing a day or two is not a big deal. We just do indoor games, like trick training (mental exercise) or playing fetch inside.
I realize not everyone has the privilege of having dog parks close by, or a parents house with a fenced in yard, etc, but I'm just giving you some ideas of what I have to do.