Unleash your natural stride and build efficiency with each step by slipping into the Isaac S. 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 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 stability guidance runner designed for everyday training and slow-paced running. It is the most traditional, structured and supportive shoe in the Newton line, and is designed to help runners new to the natural running experience. ; Breathable closed mesh upper. ; Lightweight synthetic overlays. ; Metatarsal stretch panels. ; Fabric lining supplies a soft step-in feel. ; Accommodates most orthotics. ; Second-Generation Action/Reaction Technology: A highly responsive, trampoline-like and engaging midsole cushioning that protects and loses less energy with each step. ; Single-density, high-rebound EVA midsole. ; Mid-foot support chassis provides enhanced stability. ; Heel/ Forefoot Differential: 5mm. ; Beveled heel and toe. ; Met-flex for enhanced forefoot flexibility. ; Durable carbon rubber outsole supplies reliable traction. ; Increased toe spring. ; Pronounced heel rocker. Measurements: ; Weight: 9 oz ; Product measurements were taken using size 7, width B - Medium. Please note that measurements may vary by size.