Sometimes the best thing you can do for your dog is to drop the leash. Of course only do this in a safe space where your dog is not going to get hurt. Training your dog is about shaping the behavior through operant conditioning and should be fun. If you do those things right your dog should want to be near you since they see you as part of the picture of reinforcement. Dropping the leash forces you to train without manipulating your dog and forcing them to move while will only cause confusion.