hey JaW, if your goals are to get/remain cut, then yes, you should definately do cardio on your off days, but not 'A LOT' on one day to make up for the whole week. If you lift on Thurs, Sat, and Tues, you should do cardio 2-3 days a week, like on Mon, Wed, and Fri for example. And as far as what kind of cardio you shoud do, you should do HIIT. This type of cardio maximizes fat loss while minimizing muscle catabolism. And dont forget to have a pre and pot-workout shake or meal on your cardio days.
check it out at:
http://www.youronlinefitness.com/Fit...l_training.htm
http://www.bodybuilding.com/teen/justin6.htm