Now, before you get carried away with the playground jokes, the 3-Sum isn’t what you think (get your mind out of the gutter, bruh). Rather, it’s a highly regarded triathlon shoe from zero-drop experts Altra.
Designed for the ultimate triathlon experience, the Altra 3-Sum is a versatile trainer built specifically for the needs of triathletes. It’s lightweight, fast, surprisingly well-cushioned for being a zero drop shoe, and has a quick-draw lacing system for a seamless transition to the next leg of the race.
The 3-Sum features a one-piece mesh upper for a sock-like fit, and is reinforced with synthetic overlays in areas like the toe box and midfoot for lightweight support. The shoe is loaded with a dual layer EVA midsole for the best in both comfort and responsiveness. It also comes armed with an anatomical blown rubber SpeedPod outsole for reliable traction on the road.