Merry Christmas Cigarlung,
I just had a Padron 2000 maduro with some Maker's Mark.
I did a significant amount of running for 4 months starting in June leading up to the Maui Marathon this past Sept. My motivation was that I always wanted to run a marathon and I also wanted to see how all that cardio would affect my diving.
I tracked my heart rate every morning during training using a fingertip pulse oximeter and by the end of the 4 months, the HR was down 8-9 bpm. I also lost 5-6 lbs and felt lean, fit, and fast.
The downside was that I knew my diving suffered because my legs were always sore and I seemed to constantly be in a certain state of recovery. I was also addicted to the runner's high and the endorphins associated with long-distance running; so much so that I'd get cranky if I didn't run for a couple of days. I also started a pretty significant coffee habit, something I haven't quite kicked.

I guess in the end I felt like I had become a much better runner, but not much else!
I read this one thread recently from the past that really shed some light on the topic of cardio and freediving:
http://forums.deeperblue.com/freedi.../63781-cardiovascualr-fitness.html#post569118
I'm really cutting back on the cardio now and I'd like to see where that takes me. Believe me, it's hard coming from an aerobic sports background. I'm doing mostly apnea walking and jogging with an HR monitor at less than inhale volumes aside from my usual diving. It is too early to tell the difference, but I just had an CBC blood test done showing my RBC and HGB stats (they were on the low side) and I will test again in a few months.
BTW, this is partly why I think freediving is so neat, in a geeky/cool way, you get to play with and understand your body in ways most people never dream of!
I don't want to discourage you from running or say that one cannot do both. I'm just sharing my story and experiences. Best of luck and Happy New Year!