Newton Running's top-of-the-line stability performance trainer is the ultimate shoe for Natural Running. Get a fast, flexible ride with greater energy return and less impact. The 2010 model has medial posting to offset pronation, enhanced durability in the heel, a new high-rebound midsole material and improved upper fit. This shoe allows you to run naturally — faster with greater efficiency and less overuse injuries (like achilles tendonitis and plantar fasciitis). Recommended for any distance just like its complimentary race-day partner the Stability Performance Racer. For new customers, our shoes tend to fit smaller than many common running shoes. With every shoe there is an adjustment period.