Im a pretty typical mesomorph, and if you're like me, I'd recommend taking an ECA for one or two days per week, and doing some mid paced cardio for about 25 mins on the days you take ECA. I find one day per week works well for me, and keeps teh fat in check..
If you're an ectomorph, then do no cardio, no ECA, and for that matter, I'd probably be using ProLab nLarge2 a few times a day to add a good amount of calories, fat and protein to your diet. This stuff is great for bulking up hardgainers. I even take it some nLarge sometimes when I bulk (for about three week out of each cycle), its good stuff!!!