La Sportiva Electron

[technical trail runner]

“This shoe excels when ‘trail’ is a generous description,” said one tester after a month of ankle-breaker outings on Vermont’s Snake Mountain. “On rocky, rooty, stair-stepped terrain, the Quantum absorbed shock and bad foot placement like a full-suspension bike,” he reports. Sportiva’s innovation starts with the ripple-shaped rubber sole—made from the same grippy rubber the company uses in climbing shoes. The sole is layered over an airy PU* foam midsole that maintains maximum shoe-trail contact by warping around ground features without tripping you up or throwing you off balance. “When I stepped on sharp rocks, I didn’t even feel it,” reports another tester.

A firmer, ergonomically sculpted EVA layer above the foam, with an inset TPU heel cup, adds stability and torsional stiffness. The fabric upper is built on a slip last, which means that the upper is sewn into a socklike shape, then glued to the midsole without the stiff, boardlike layer typically found in heavier-duty shoes. A slip last, often used in climbing shoes, best mimics the foot’s curved shape, and the result is a shoe that wraps your foot more closely when you lace it snugly, reducing friction and the chance of blisters. “The close fit made running downhill a joy—nothing shifted even in tight turns. When I weaved around trees, the Quantum felt like an extension of my foot,” says one ultrarunner after logging more than 250 miles in the shoes. “I had the perfect amount of sensitivity.”

The meshy upper drains well and testers reported it didn’t trap heat. With the toe bumper, stretchy scree guard over the tongue, and reinforced p-cord laces, the Quantum won’t wear out fast like fluffier runners. Take it hiking, too: It can handle 30-pound loads in all but the slickest terrain. Bummer: The rippled sole doesn’t grip well on wet, grassy slopes or slimy rocks. $115; 1 lb. 10 oz.; m’s 38-47.5, w’s 36-43