Each shoe contains a microprocessor capable of making 5 million calculations per second. A magnetic sensor in the shoe's heel measures its compression on impact, taking 1,000 readings per second. A secret algorithm (Adidas engineer Mark Oleson says they intentionally omitted it from the patent) decides on the optimal amount of cushioning required. To achieve that, a tiny electric motor, spinning at 6,000 rpm, turns a metal rod that adjusts the hollow plastic heel. All of this is powered by a replaceable 3-volt battery said to last for 100 hours.
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