Woke up today and my heart was beating at about 72 bpm. Normal, but it felt fast to me for some reason. After seven hours, eating (which boosts the metabolism), drinking coffee (which also boosts metabolism), and the like, my heart rate is 63 bpm.
Could be a sign of overtraining. To be paranoid, I'm taking the day off from running, especially since it's speedwork. Besides, my body feels pretty tired and my throat feels scratchy. Though they sound like excuses, they really are reasons, and I'd love to go to speedwork today if I really felt like it were a good idea.
But it doesn't, and I can live with that. :)