Your feet are the closest things to the ground. Shoes inhibit natural movement of the foot and weaken the underlying muscles. The 2620’s help passively exercise your feet while you are making a new PR.
Running
Running barefoot is far more energy efficient than running in shoes. It is also impractical.
The 2620s are designed to encourage the foot to move as if it was barefoot but with the added bonus of being protected with shoes.
