The 3-Sum™ is the sum of the three event triathlon experience. Lightweight, fast, and lightly cushioned, the 3-Sum™ is built for triathletes who demand the ultimate in performance. With a seamless upper, easy-on transition pull-tabs, quick-draw lacing system and heel/forefoot drain holes, the 3-Sum™ minimizes transition time and maximizes performance.

The Zero Drop™ design allows for natural loading of the calf and Achilles while optimizing the landing angle to ensure powerful speed with minimal impact. The Altra 3-Sum™ – get off the bike and run like there is no tomorrow!