Run further than you thought possible in the GEL-NIMBUS® 21 running shoe for men by ASICS - packed full of plush cushioning and special technologies to respond to your natural stride. The GEL-NIMBUS® 21 shoe is fitted with our I.G.S® (Impact Guidance System) technology: a construction technique that allows the shoe to respond to your natural gait. The TRUSSTIC SYSTEM® technology provides added stability so you can focus on pushing yourself further than ever. The upper is made from Jacquard mesh and will fit snugly, allowing air to flow and keep the foot fresh as you run and run. Our famous GEL® technology in the front and rear sole gives you energized cushioning in the form of shock-absorbing silicone for heavy-impact activity. Meanwhile, FLYTEFOAM® Propel technology in the midsole offers excellent bounce and toe-off. This lightweight foam formulation has a special high-energy return elastomer helping to put a spring in your step. Gain even more bounce with our SpEVA insole, which also helps the shoe last. To ensure a great fit, there's an external heel counter which holds your heel firmly, keeping you comfortable as you pound the miles.