A Couple More Running Thoughts:
Cadence is an important aspect of barefoot running. If you try to take long, loping strides, you end up over-striding, which causes extreme friction on the skin, pounding on the bones, and each forward stride stops your forward momentum. By increasing the cadence, you simply don't have time to stretch your foot out in front of you, so instead, you plant your foot directly beneath your body mass. Some runners carry metronomes to help them keep a good cadence going. The best cadence is 180 steps per minute, 3 per second.
I found that by repeating the word "Am-ster-dam" in my head, it helps set the correct cadence. That got boring, so I started looking for other things to repeat.
I thought of a song I had sung in a church choir, which had the words "Ju-bi-la-te, Ju-bi-la-te, Ju-bi-la-te, Ju-bi-lay" with a nice catchy tune. One time I ended up "singing" "Hal-le-lu-jah, Hal-le-lu-jah, Hal-le-lu-jah, Shout Hur-ray!" I don't know where that came from, but either version is not quite as boring as just repeating Amsterdam.
Some others I have come up with are the words to "Onward Christian Soldiers" - at least as many of them as I can remember. Sometimes I forget the words to a song and end up mixing parts of different verses all together, or else just make up words that seem to fit. I don't think anyone who knew the song would recognize it after I was done re-mixing it!
In the Stake choir I sing in, we just started rehearsing a song from Handel's Messiah, so lately I have been "singing" to myself something like, "Forrrr un-to us a Child is gi-ven! (Un-to us) A Child is gi-ven" etc. and "Haaaaa-le-lu-jah! Haaaaa-le-lu-jah! Halle-lu-jah! Halle-lu-jah! Ha-a-a-le-lu-jah!" etc.
Those are fun ones to run to. Since I am doing this in my head only, I can sing the different parts, soprano, alto, tenor, bass - whatever.
Whichever of these tricks I feel like doing, they all seem to work pretty well to keep me on a 180 beat cadence.
When I get one of these things going nicely in my head, when my running form is "on" and my cadence is correct, I sometimes zone-out and am not aware of the passage of time or distance. The other day I was just bee-bopping along and realized I had run almost an entire mile without even noticing my surroundings. There is one section of kind of tricky bridge surface I ran across, and when I "came-to" I had already run over it without even thinking about it!
Happy Trails to You!