If your going to make "gains" and do cardio then you have to eat more.
If your cardio is on a machine (bike or somthing) find out how many CALS your burning and add that to your total daily caloriac intake.
So if your going for a lean bulk you should be eating about 3,000 - 3,500 cals a day. if you burn 400cals running then make sure you add somthing to your diet that day.
FYI dont expect to make good size gains if your not eating alot. most people who are looking to gain about 10-20lbs of quality LBM and retain it eat more than 4K of cals a day.
Just somthing to think about.