I have been a consistent endurance runner for 8 years, running countless half-marathons, 10ks, and 5ks. I also completed five full marathons, and this last fall was the 1st time in five years I opted to only run the half. I'm almost 38 (03/07), but I think I definitely hit an over-training period last year around this time.
I've also been a consistent weight lifter (10+ years) @ 3x/week. I decreased my running from 40+/week to 15-20/week, but kept lifting going, even increased it to 4-5x/week. Before, my hamstrings were constantly tight/aching and resting heart rate was as high as 210 bpm. I'm normally at 38-40 bpm.
I admit that I read TOO much on the Interwebz and how bad running is for you, so then I almost completely stopped altogether. But something in me just didn't feel right, so I've gone with my instinct and I've continued to run. You really have to listen to your body.
Another no-no - I thought I could speed fat-loss by training fasted. Not good, especially since I'm iron deficient. My workouts suffered, as well as my overall energy. It's just not for me.
Darrin, thank you for your informative blog and this forum. 
Emy