Dogs only know the moment,,,hitting after just says you suck at this moment to the dog...

reward as soon as you see good,,, like sit,good boy/girl,,,treat... when he wants to run jerk the collar and say something loud like APP,,,done because that is the only moment you can correct it... sit him,,,good boy,,,treat... he will eventully,,,most times quickly,,,be so intent on getting a treat he will forget the pulling...