and further for what its worth, I find that as well as yoga, barefooting in natural terrains: rocky coves, sandy beaches, fields, parks, rivers, hills, gravel pits, etc is superb wholistic conditioning.
Firstly, one is compelled to shift the awareness into the feet and so one slows down the often usual mind-commentary that takes one away from being present.
In addition, in order to walk in a variety of terrains one needs to walk correctly, which happens naturally of its own accord as one devotes more time to the activity. In short it hurts both the feet and hips, knees and lower back if one doesn't walk gently in accordance with ones own unique biomechanics.
Modern shoes with thick padding and built up heels promote heel striking and 'mindless' thudding about, whereas when one is barefoot the first point of contact is much further up the foot.
Also, in order to navigate ones way through various natural terrains (or urban ones too) a flexibility in the entire lower portion of the body develops, as associated muscles and joints are spontaneously conditioned as the feet and ankles morph, flex and adapt to the terrain.
In time, the entire lower body becomes more flexible and movement 'strong'.