Here’s some more supportive data on the benefits of running barefoot and an interesting analysis of force distribution with an without shoes.
Born to Run Barefoot - John Dodge
To clarify our recommendation is that athletes run 5-10% of their weekly mileage barefoot on a soft surface. So for the athlete running 20 MPW that’s 1-2 mile per week barefoot. We are most interested in the variance of foot strike, flexion and force distribution which helps strengthen the plantar facia, achilles tendon and calf muscles.
The article includes two videos from the Harvard University Skeletal Biology Lab that outline the force variance of barefoot running.
They can be viewed here: