I have read many scientific arguments on whether regular exercise elevates the mood and helps treat depression. Well the question is what comes first? How you feel about and approach the exercise in the first place will go a long way in determining on whether it is a pleasant, mood elevating experience or a negative cognitive stressor.
I forgot to mention that I go into this further in Flight or Fight: Lift or Die in the section entitled Exercise for Stress
If you must exaggerate to make a point, then you're must not be very good at making points.
