hi bv,
another excellent post. i have never been advocating my level of exercise for the average person. but for optimal health, here is what i would advocate.

exercise as much as possible, and eat carbs to fuel that level of exercise. we all have to understand our bodies, and exercise to our capabilities. there is always that person you see jogging on the street, that you know should have stopped miles ago. this is not healthy, in the slightest - just look at the marathoners, many of whom are eating up their body.

my most vigorous cardio routine i do twice a week at that level of intensity, there is no way that i could or would do it every day. the weightlifting for me, plays just the opposite effect - instead of vigorous movements, it is slow and controlled, and i would say mostly at a fat-burning level. i don't burn tons of sugar until i start doing cardio.