Since natural running took hold of the running world, shoe designs have slowly become lighter and lower to the ground. The Altra Women's One 2. 5 Running Shoe offers both of these characteristics but with a unique twist. Inside and out, this shoe is shaped like your foot. Inside the FootShape Toe Box, your toes have room to spread out and relax, and toward the heel, the fit tapers down to cup and secure your heel. Although fully cushioned, the InnerFlex midsole feels light underfoot and flexes in line with your joints. With the Zero Drop platform, you get the most natural foot position, a powerful toe off, and a smooth transition through your stride. Plus this shoe weighs in at a modest 5. 2oz. Among Altra's running shoes, the One 2. 5 is unparalleled when it comes to speed work or comfort over marathon distances.