Originally Posted by M.W.
-Cardio should be a focal point of your routine. In order to look lean you'll have to maintain the upkeep in order to stay lean which entails plenty of cardio. 20-30 minutes a day of moderate or high intensity should be fine for you.
I agree with cardio being important, but high intensity cardio burns muscle not fat. You have to do longer periods of low intensity cardio to stay lean. If you do 30 minutes of high itnensity, you are hindering your progress.
As far as training abs. If you are doing things like squats, or off balance weight exercises then you are training your abs already.
If you really want to lose fat, and keep muscle look into the Dave Palumbo cutting diet. I have used it, and saw insane results. Lots of people use it for getting ready for competition to lose down to 3% body fat, but keep their physique. It's tough to follow, but worth it.