For middleweight to slightly heavier trail runners. For trail runners who run in difficult environments, e.g. on rocks rather than gravel roads. For long-distance trail runners. This shoe is fully equipped with Mizuno proprietary features to keep you comfortable even on the toughest terrain. The shoes are fully equipped with MIZUNO ENERZY and MIZUNO WAVE Foam from heel to toe, offering excellent cushioning, energy return and stability. Support panels on the sides of the midfoot keep the foot firmly in place, even on the toughest trails.