Craig,
Man, I work my butt off every day, swinging a hammer and scratchin' my head...what other physical activities do I need?
If you manage to do these both at the same time I suspect that you need no excercise, but you may need a therapist.
I run three times a week and have done since my early twenties. These days the seven miles are down to just two but it is enough to ensure that I prolong my miserable life in the God-forsaken and utterly pointless moment of cosmic consciousness, otherwise known as my life on that planet.
The jury is still out as to whether exercise helps your mental well-being, but I think it does......honestly....
HS