Providing unsolicited advice since 1996................
No picture today. Short and sweet. Try running barefoot (wear socks) on debris -free grass field. Give it about a 5 minute effort and build to 20 minutes. Do it once a week. The African runners are some of the most efficient and it's correlated with HOW they learn to run as youths. If you imagine running barefoot on pointy pebbles, hot coal, sand spurs, summer asphalt........whatever, you can picture that you would have fast feet and would probably strike mid-forefoot first, rather than heel to toe. Remember, contact time with the ground slows us down. Fast feet are those which are not touching the ground, but moving forward through the air. A mid-foot strike w/ hi rpm and forward lean will result in less contact time. Hence, moving forward at a faster rate.
That is the last you'll read about this topic from me for a while. It is time to move on the other things.