Footwear technology is always evolving, as the latest offerings from Under Armour and Topo reveal.
Most running shoe companies start as shoe makers and follow by bringing clothing to market. Under Armour (UA), which was an apparel manufacturer first, knew it had yet to impress runners with its footwear and needed to do something unusual if it was going to make a splash in the market. It has, with the SpeedForm shoe ($120), which gets its inspiration from an unlikely spot: bra molding.
The design is intentionally simple. UA formed upper materials in two preshaped sections that fit together like a clamshell. Where a typical shoe might have roughly 20 parts comprising its upper, the SpeedForm has three. Fewer parts and no stitching allow the shoe to smoothly conform to the runner's foot, with none of the rigidity that seams enforce. Instead, ultrasonic welding holds the shoe's upper parts together. There is no insole, and a bra-like, cupped shape in the heel anchors the foot.
The SpeedForm is visibly different when you look down at it from the top. Isolated toe undulations wave across the upper, positioning the toes with a snug fit, but one that doesn't bind.
The manufacturing advancements that UA opens hold promise, especially when this ingenuity is combined with evolving 3D printing. Because the manufacturing process uses far fewer parts, the labor reduction is significant, removing about two-thirds the number of human hands from its assembly and, hopefully, leading to better working conditions and domestic production.
Mitten running shoes, which separate a runner's big toe but keep the other four toes together, may appear to be an evolution of five-finger glove shoes, but have been around longer than most people realize. They date back to at least the 1920s in Japan, and 19-year-old Shigeki Tanaka won the 1951 Boston Marathon wearing the "tabi" split-toe shoe. Nike tried the design with the Air Rift in the 1990s and ASICS brought the design back in 2006, with the limited edition Marathon Tabi.
Within the last three years, split-toe shoes have come out in force. ZEMgear, B2R and OluKai took mitten models to market; Body Glove 3T Barefoot designed three-toed shoes, which separate the first and second toes in their own compartments but let the last three hang together; and Fila's version has four compartments, coupling only the two smallest toes. The variety of lobster-toed footwear ranges from minimalist aquasock style to more built-up versions.
With the mitten, the idea is that the natural spread of the big toe allows for better proprioception and toe-off, and the separate compartment anchors the forefoot throughout the gait, especially on descents, when runners often experience toe smashing in conventional running footwear. Mitten shoes are easy to slide on, and for those who dislike wearing them barefooted, Injini makes mitten socks that accommodate the separate big toe.
The most technologically tricked-out model of all these is the recently launched Topo Athletic RR (SRP $130). With a laterally placed Boa Closure System that uses a thin steel cable, the shoe tightens with the turn of a dial for a speedy, precise fit. The security system keeps the RR snug to your foot in a way that laces do not, and holds your foot well enough that you don't feel any chafing in the sensitive spot between the big toe and second toe. Like the UA SpeedForm, the Topo model uses heat welding instead of stitching for extra comfort -- no socks necessary.