I'm still not sure how this works. Sometimes I feel like I'm prepared for my run; I'm psyched up, my mp3 player is charged and then......pfffffft. I can't get my groove on when I run. I feel out of step, tired, just can't seem to keep going. Other nights (like tonight), I'm not really particularly in the mood but I'll go out anyway and see how it goes and BAM! I hit the rhythm almost instantly and the whole run feels good. My breathing is good, my pace is good (slow, but steady), and it all just gels.
What gives? Is there a method to this madness or is it just luck? The other night I totally ran out of steam and didn't realize till I got back to the house that it was probably because I hadn't eaten for over 6 hours. So that one I figured out, but for the life of me I can't predict whether my run will be smooth and swingin' and enjoyable or a big old sweaty struggle.
Another question: Do you find that the songs on your playlist have to have a certain rhythm? Do you run in time to the rhythm? Usually I do, or try to (because I find it distracting otherwise), but tonight a song came up and the rhythm wasn't quite right but it was such a happy, fun song that I kept it on anyway and didn't really care that it was the wrong tempo--I was able to maintain my running pace even though it was different from the song. How important is the tempo of your playlist?

When I first started running, I spent AGES researching optimum BPMs (beats per minute) and testing all my songs against my natural rhythm, etc, to try to match them up. I found though, that when my energy level was lagging, the songs that pulled me up weren't those with an ideal tempo, but those that just made me feel good! The ones that got me singing along in my head (and yes, occasionally out loud!) and that made me smile. So now I just go with those and ignore the tempo altogether. Would be interested to hear what others do?
I'll purposely skip over songs that I know are too close to my natural running pace.