His test results were published during the Nike sub2 project a few years ago before he ran 2.00.25 at Monza.
Since then Nike have been continuing to work on improving the shoe technology.
What makes elite distance runners more economical seems to be a combination of a 70ml/kg/min oxygen uptake or thereabouts and a 51 second 400m ability or thereabouts, combined with the right training.
There is no secret magic bullet. But we also have to take Kipchoge's personality into account. He is obviously very dedicated to his profession and easy to get along with.
It's disappointing to me that so many silly old men want to poison young people's minds with these endless drug endorsements, whilst pretending to be anti-doping.