Q: How do I know if my dog is getting enough exercise?
A: You will know when your dog is getting enough exercise when they voluntarily chill themselves out after a long walk. Depending on how long it takes them to recover from the walk, you'll know how many more walks they can handle per day. In my experience, every single dog needs at least one hour of exercise per day.
Whether that be walking through the neighborhood or backpacking through the canyons, every dog needs challenging exercise every single day. Your dog will also respond better to the rules you set in the household when you've exercised them sufficiently. I say this so that you understand how your dog responds differently to the rules that you set when you exercise them.
When they're exhausted, and you've met their exercise needs first, they're much more likely to submit to your disciplinary boundaries. And when they're not exercised first and they don't have their needs met, they're much more likely to challenge you on those rules, because they haven't had their need of exercise met first.