These are the insoles that help a runner go faster or farther with less fatigue. Available only from Hammacher Schlemmer, the insoles go miles beyond common activity trackers, recording the force applied with each step, the area of your foot that bears the most pressure, the amount of time your foot spends airborne, and other useful readings—they even alert you to injury risks. Data is sent wirelessly to a smartphone app that displays gait analysis in easy-to-read graphs to help you correct biomechanical flaws and develop a more fluid, efficient stride. In addition, the app records distance, steps, calories, average speed, provides real-time audio coaching, and displays a 3D map of your route. The insoles store up to 10 hours of activity and their lithium polymer battery lasts for seven days on a two-hour charge via USB. Made from two layers of polyurethane covered with an anti-bacterial fabric, the insoles are undetectable underfoot and feature a stabilizing mid-sole and flexible arch for superior support and comfort. For iOS 4S and above and Android 5.0 and above. Sizes M (men’s 7-8, women's 8 1/2-10), L (men’s 8 1/2-10, women's 10 1/2-11 1/2), and XL (men’s 11-13). (14 oz.)