Take one look at the wall of your local running shop, and you’ll see that cushioning has made a huge comeback. Seemingly every company has a bulky trainer with an oversize foam slab. And, while Adidas recently found great success with its Boost midsole material, it wasn’t quite a player in the “maximalist” game until it launched the Adidas Ultra Boost recently.
Over the past few years, Adidas has been rolling out Boost — a TPU-based material instead of the customary EVA foam that nearly everybody else uses — to all of its performance running shoes that cost more than $100. The midsole material has proven more durable, responsive, and resistant to temperature changes than EVA midsoles. While Boost is often mixed with stiffer materials for more stable shoes, Adidas uses a full-length layer of it for the company’s neutral runners. The Ultra Boost gets an even thicker midsole layer than any existing shoe in Adidas’ lineup.
The result: A luxuriously soft ride — especially in the heel, which is its thickest point. Yet the shoe resists feeling mushy thanks to a thinner, flexible forefoot. That allows the shoe to bend freely on toe off, so you get a shoe that “feels” fast.
Most attention will be given to the shoe’s soft ride, but we really like its traction. A rubber web criss-crosses the bottom of the shoe, in a pattern reminiscent of a tennis racquet’s strings. And at each intersection, it’s bumped up to create a small nub. The design provides excellent grip without the added weight you usually get from a full-length rubber outsole. Those nubs, admittedly, showed signs of wear pretty quickly but were still holding strong after more than 100 miles.
The upper, too, is impressive. It’s the first real Adidas running shoe we’ve seen in the United States to use PrimeKnit — the company’s knitted fabric, much like Nike’s Flyknit. The stretchy, seam-free upper hugs the foot snugly, but some runners with wide feet will find it a bit too tight — especially across the top of the toebox. Another knock is the needlessly thick saddle: The tight-fitting shoe almost doesn’t need that extra support — we set out for at least three runs forgetting to tie the shoes first — and it has a tendency to rub your foot. Fortunately, it didn’t cause anything more than a minor annoyance.