I am a industry insider.
The foam itself cannot give you MORE energy than you put in. It the higher energy return of the foam the more you get back. It is a form of spring in pure engineering terms.
The Carbon fibre leaf type spring hidden inside the Nike shoes works similar to Pistorious's foot. I believe it works in a couple of ways, directional propulsive energy return, and by changing the human biomechanics. The propulsion was a word commonly used in early Nike PR that has since been removed due to the obvious negative connotations. Plenty of google evidence from
Nike spokespeople who mentioned the propulsive benefit then after the initial backlash changed their story. The carbon leaf spring potentially lengthens the stride similar to Pistorious at the end of a 400m once he got up to steady state speed. It also potentially minimises bending at the inefficient metatarsal joint transferring more load to the more efficient Achilles and valve artificially changing the biomechanics of the runner. These changes explain why there have been several Injuries in the shoes and complaints about sore legs.
However what everyone is missing is the drafting effect of the big fÃ¼Ã§k off TESLA with timing board that has been specifically told to stay 5m in front of the runners.
You can argue about the shoes but this whole thing is irrelevant unless they get rid of the pace car, and the jump in pace makers.
Classic Magicians ðŸŽ© trick. Hey everyone, look over here at this shoe. Makes them miss out on the Wind blocking draft inducing TESLA.