I tend to not do enough of the 'essential to life' things such as eating, sleeping and drinking water. To be honest, most of the time it doesn't occur to me that I need to do them. I go without eating until I'm lightheaded/cranky/starving to death, I go without sleep until I realize it's late and I should probably go to sleep (one of the reasons I keep a scheduled afternoon nap!), and I've had days where I can't remember drinking a single drop of liquid.
Now I know none of these things are good and I try my best to be conscious of them. Recently though, I started to notice a trend.
My 'bad' runs (where my legs felt heavy and movements felt forced, the ones where I'd feel my lungs cramp up) occurred after days of less than stellar hydration. Duh.
Since I've been really paying attention to my water intake my last few runs have been much better, I'm still sticking to two miles, but hope to be able to increase it soon.