i don't know what a 'runner' is, but what you are describing sounds like a sidearm/lateral. along the vine, at each junction where the leaves emerge, there usually will be two sidearms that develop growing outwards away from the main vine. these lower sidearms and lower leaves can impede air circulation near the base of the vines if too many vines are trained and the area gets a little congested. sure, they may produce some hops, but most of the upper laterals/sidearms bear the brunt of the hops. removing the lower laterals will remove a little bit of your harvest, but will improve air circulation and create an environment much less hospitable to disease development. roll the dice and hope they come out in your favor. you may never see any disease in your plantings and all will seem well. on the flip side, you may be inundated by downy mildew and wonder why your plants don't produce. these are extremes, but can and do happen in the real world. live and learn, but make sure you have a good beer nearby!