Dogs were traditionally working animals. They would have expected to be active all day, every day. However, in these modern days a dog's life can often be confined to indoors and with very few physical activities.
Dogs are animals that need exercise on a regular basis; in fact it should be daily.  There are many reasons for this.  For example, it can help to control the dog’s weight its appetite.  It can also help to insure good quality mental health as well.  If you do not provide for the dog’s daily exercise, she will likely find it in her own way, which may be a destructive manner.  A dog that is bored is one the can become destructive digging up the yard and chewing on shoes.  But, when you take this energy that the dog has and apply it correctly through various toys and exercise, great things can happen.
One game of catch a day is not enough exercise for your pet.  Quantity and quality are quite important.  For example, you can provide your pet with a daily walk.  If you do so at the same time of the day each day, the pet will begin to look forward to it.  And, take them to someplace different as often as possible.  This will help your pet to explore with his senses.  It is also a special time of bonding between you and your pet.  Take your pet to a dog park where the leash can come off and he or she can do some socializing with other animals.
Sports for dogs?
Did you know that dog’s can do sports as well?  There are many things that you can teach your dog to do that will be fun to play and provide them with the exercise that they need.  For example, Frisbees are a great choice as is flyball and agility.  There are Frisbee competitions that your dogs can participate in.  In this case, you’ll see pets flying into the air to catch the Frisbee that an adult is throwing.  You may see the dog twist and jump at the same time. In fact, some of them are choreographed routines that are nothing short of amazing but they are fun and exercising for the pet.  
Flyball is another choice.  Here, there is team play.  Four dogs per team take turns running through a course.  They may have hurdles in them as well.  When the dog completes the course, he will trigger a box to will force a tennis ball into the air.  The dog catches it and races back through the course again.  Then, once the dog gets through, the next team mate goes.  A team will win based on time and the fewest errors.
Agility is another sport for dogs.  Here, the dog is to run through an obstacle course.  The goal is to be done in the fastest amount of time.  In this sport, though, the owner will run alongside the dog encouraging it over the hurdles and other obstacles.  The goal is for the dog to obey the owner’s commands and directions.  A good doggie workout will include things like tunnels, see-saws and a wide variety of jumps.  All of these sports allow for the exercise of the dog as well as the mental fitness he needs as well.
Alternatives to sports?
Not sure if the sport is right for you?  You can keep your dog going by giving him toys that will help to stimulate not only exercise but also mental challenges.  For example a dog puzzle places a treat for the dog into a hollow container that he will have to work off to get to the treat.  Through nosing it around and rolling it, the dog gets the treat and the reward.