That old formula that was taken from the Dr. Cooper is dated. It doesn't matter what fuel you are burning during cardio whether it's fat or sugars. What matters is the total caloric cost of the activity. In other words the harder the better in a healthy individual.
One thing for lifters is that they don't want the cardio to interfere with lifting. I think fast walking on a treadmill using the incline feature is perfect. I'm a runner but walking fast on an incline will kick anyones ass.
