Cardio is tricky. If your body is functioning like the perfect machine that it is, I reccomend any sport or light jogging. If its not, then I would reccomend none. You have to build function before you start your cardio. This includes clearing all the obstructions in your joints and making sure all your muscles are turned on. That is precisely what my program does. Doing any repetitve cardio over a disfunction always leads to bulking. To keep your body from overdeveloping in certain places, getting any injuries, and to make sure you can move through all your movements with the most strength as possible, creating the proper function and ensuring your biomechanics are spot on are the first step.
That was the longer answer. In short, if you bulk easy, don’t do any cardio until you have sufficiently eliminated any and all bulk or over-developments in your muscles.