When you train your dog, don't allow your efforts to be diminished by an excess of trainers. Many people do it differently than just having a few commands to give your dog. Pick a single person to be responsible for all training, and let others support the decisions made by demanding the same standards of behavior from the dog.
Just like people, dogs need plenty of exercise for optimum health. Dogs are naturally hunters and love to run by instinct. Take your dog to the park, play Frisbee with him and give him a daily walk. This will help keep him physically healthy but will also make him mentally healthier.