Tempo or endurance run?No matter the variables, the one thing that won't change is the consistently reliable ride of the Gravity. Adaptation Period: ; Adjusting to Newton running shoes will depend upon several factors including: your current running shoes, your running form, gait efficiency, as well as your speed and flexibility. Those new to natural running form, or those transitioning from a shoe with traditional cushioning will benefit from spending adequate time adjusting. Your body will need time to lengthen the muscles and tendons on the back of the leg and under the foot. Newton recommends that first-timers walk in their shoes for several days to become accustomed to the level platform. Walking barefoot on safe and comfortable surfaces can also be helpful. Once ready, begin by introducing short runs of no longer than 15 minutes every other day. Gradually add 10-15 minutes as your feet and leg muscles begin to strengthen. If soreness persists for more than two days, reduce time in shoes immediately. Rest and ice until soreness subsides, then slowly begin introducing time in shoes again. A running shoe built for the neutral runner looking for a daily trainer that is versatile enough for fast tempo runs and races. Fast-drying, open mesh upper. Minimal synthetic overlays. Metatarsal stretch panels. Plush tongue and collar for added comfort. Fabric lining supplies a soft step-in feel. ETC antifriction, antimicrobial sockliner promotes a great in-shoe environment. Accommodates most orthotics. Action/Reaction Technology: A highly responsive, trampoline-like and engaging midsole cushioning that protects and loses less energy with each step. High-rebound EVA. Biomechanical Sensor Plate allows the foot to sense the ground promoting a lighter, more efficient stride. Differential: 3 mm ; Met-flex for enhanced forefoot flexibility. High-density rubber outsole. Carbon rubber heel. Imported. Measurements: ; Weight: 9 oz ; Product measurements