Serena Williams in her Nike Lunar Hyperworkout+ trainers
What are those amazing trainers on tennis player Serena Williams' feet at a recent Nike Training Club Schools event?
The brand new Nike Lunar Hyperworkout+ is an amazing new high-tech shoe with built-in sensors that measure how hard, fast and often you train, while a link with the Nike+ Training app turns your workout into a game to keep you motivated.
Comfort is covered too, with Lunarlon cushioning and Flywire to provide great support while you tone up.
It's not on sale yet - but due for release this summer.