Sizing: Standard running shoe lengthHeel: MediumMidfoot: MediumForefoot: MediumToebox Height: Medium to lowArch Structure: Medium to highShoe Shape: Semi-curved TheNike Zoom Structure 20 is a moderate support road running shoe that offers an ideal blend of cushioning and comfort. The shoe is a great option for training over any distance.*Runner’s World is a registered trademark of Rodale, Inc. All rights reserved.