Running board dimensions
Assuming this is a basement, 14, 12, and I believe 10 cable are required to either be on a running board or drilled through the joists if they are running perpendicular to the joists.  Larger and smaller cable is not required to be on a running board.  I believe this was done because people were using normal cable for receptacles and lighting as clotheslines in the basement.  Keep in mind codes have changed over the years and just because it was legal when the electrician installed ungrounded cable in an asbestos jacket in the 50s doesn't mean it's legal to install it today.  The existing construction can remain, because it was built to the code at the time (assumingly), but if it falls into the scope of your project the only way you're going to pass an inspection for a permit is if you bring it up to code.  

Also, if you drill a hole through a joist, make sure you drill in the center of the joist.  This is because the joists are beams supporting a vertical load.  Think of when you see a board with a heavy load, sagging in the middle. This displays compression on top and tension (pulling) on the bottom.  In the very middle, where the board transitions from compression to tension, there is no load, so drilling a hole in the middle will have minimal structural effect.