Sole Power

Adidas's new Springblade certainly looks revolutionary—but does it make you faster?

Adidas's new Springblade running shoe is an odd piece of footwear, appearing as if it's been sent from the future. Translucent tines—looking like Oscar Pistorius's hi-tech Cheetah prosthetic blades—jut out where a normal midsole would be. It's a jarring new design, one that was six years in the making.

When a runner's foot strikes the ground, it compresses the material—EVA foam, usually—between the foot and the bottom of the shoe. But remember high school physics: For every action there's an equal and opposite reaction. A runner's speed depends on how hard he or she pushes down on the ground—that's how hard the ground pushes back. The more material, the more the force is displaced; the more the force is displaced, the more the runner slows down.

Enter the blades.

Each of the shoe's 16 blades has a different stiffness and angle to the ground, creating a series of individual springs that work in concert. They are angled so that the runner's foot rolls from back to front and then push the foot up and forward.

All of this sounds great, but do the blades actually make a difference? The sensation of walking in the shoes was weird at first, but as I ran, my feet were never uncomfortable and I didn't feel unstable in the shoe.

As for the advertised spring: I strike on my forefoot, so I didn't feel much more energy return than a shoe with a firm foam midsole. However, when I switched my stride to see how the shoes would perform for a heel striker—someone whose heel hits the ground first, the case for 98% of novice runners—the shoe seemed markedly different from others I've run in. I could feel the blades working together to roll my foot forward and provide a boost.

It may not make a slow runner fast, or be worth the $180 price for a runner who's not a heel striker, but the Springblade is far more than just a gimmick.

Go Figure

600

Length in meters of a charity race agreed to by 100- and 200-meter world-record-holder Usain Bolt of Jamaica and 2012 Olympic 5,000- and 10,000-meter champion Mo Farah of Great Britain.

1:2 Odds set by British bookmaker Ladbrokes on a Bolt victory.

1 Pitches on which Vinnie Catricala, third baseman for the Double A Midland (Texas) RockHounds, struck out against the Corpus Christi Hooks. After taking a strike, Catricala stepped out of the box for so long that umpire Ron Teague called a second and third strike on him.

$ 100,000

Reward announced by Cal Ripken Jr. for anyone providing information leading to the arrest of the unidentified man who abducted Ripken's mother at gunpoint from her home in Aberdeen, Md., in July 2012, and held her for 24 hours.

15

Age of Cole Custer, whose victory last Friday in the Pork Be Inspired 150 at Iowa Speedway made him the youngest winner in NASCAR K&N Pro Series history.

$497.76

Tab paid by golfer Bubba Watson when he bought dinner for more than 60 people at a Chipotle in Akron after the second round of the Bridgestone Invitational.

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TAYLOR BALLANTYNE FOR SPORTS ILLUSTRATED (SHOE)

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BILL FRAKES/SPORTS ILLUSTRATED (BOLT)

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KIRBY LEE/USA TODAY SPORTS (FARAH)

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JUSTIN EDMONDS/NASCAR/GETTY IMAGES (CUSTER)

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CHIPOTLE (BURRITO)