Depends on your goals bro. If you are after strictly size and mass then leave the cardio out until you want to cut up. If you are looking to stay fairly lean then by all means add the cardio. I once read a statement a couple years ago by an amateur bodybuilder that said, "If you are going to bulk then bulk and forget cardio...if you are going to cut then cut it up and hit that cardio. Don't try to mix and match cardio with bulking cause it will be counterproductive and you won't gain mass or cuts...you will just stall out and you won't achieve either of the desired effects you were after." I paraphrased that of course, but I think the guy has a good point. Take a long look at your goals and if you are purely after mass then forget the cardio. Use the cardio once you want to start defining that new mass you achieve while bulking.