Boing, boing, boing . . . I couldn't quite hear the springs in this shoe as I bounced down Boulder Creek Path, but I could feel their bounce. Spira sneaks metal springs into the EVA midsoles, and it's no gimmick. The lively two-inch-diameter coil in the heel puts a noticeable spring in your step and adds to the shoe's durability, because it reduces the toll on the foam. But what really grabs the attention is the overall ride of this featherweight trainer: stable and very smooth.
Bonus: The mesh upper is flexible and breathable.
Bummer: You can dust your buddies, but not the field in the Boston Marathon; the shoe is banned there because it violates IAAF and USA Track & Field rules. 11 oz; www.spirafootwear.com