Dogs need mental stimulation as well as physical exercise.  Fido will enjoy daily fun games which are easy for you to add to your daily lifestyle.  Hide five of his favorite treats around the house; like under the kitchen table, on the edge of the bath tub, in his crate, on the bottom shelf of your night stand, etc.  You might have to help your dog learn the game at first.  Walk around and use a special work like "Look" or "Search".  This encourages your dog to use his senses and to explore.

When you leave for an errand - or to go to work, get a stuffed Kong out of the freezer and lay it on the kitchen floor then walk out the door.  Your dog will look forward to you leaving as he has this tasty treat that will occupy his time for quite awhile.

Turn on a radio also when you leave.  This focuses your dog's hearing inside the house and distracts him from listening for noises outside the house.  The outdoor noises tend to provoke a dog into excessive barking or other frenzy behavior.

Daily walks are a good way to build a bond, a healthy relationship with your dog.  These are mental exercises, not physical.  For your dog to meet his physical needs, he needs a wide open area to run and stretch his muscles and feel free from leash restraints.  A TIRED DOG IS A GOOD DOG!