The following was taken from the RW Training Extra email that I
receive. This is a truism, whether a barefooter or a shoddie:

"When you practice running with a lighter, quicker turnover, you become
a faster, more efficient runner. An increased cadence also decreases
your risk of injury, because your feet spend less time pounding the
pavement. Try counting the number of times your right (or left) foot
hits the ground during a 30-second period. Jog for a minute or two and
repeat the 30-second drill eight times, trying to increase your count
by one or two footstrikes each time."

(Not crazy about the word "jog" but you get the idea.)

BR