Our bodies are fueled by calories and water. Calories are easy to carry, but water ... water makes things more complicated. To solve this problem, Ultimate Direction teamed up with ultra-runner Anton Krupicka to create the AK Race Vest. Since Anton sticks to a 'less is more' philosophy, this vest is super light and contains only the features you need. A hydration bladder, although clever in design, is inconvenient to refill and it becomes a pain when it bounces around on your back. Water bottles are a much more elegant solution, and the AK Race vest allows you to carry two at chest-level, one on each shoulder strap. Here the bottles are free from the bounce caused by running on the trail and they're easy to grab for drinking or refilling. Behind these holsters lies a harness made of highly breathable Hex Mesh, and behind that, a stretchy storage compartment comprised of Power Mesh. Up to four liters of gear stashes away inside this mesh compartment and, because of its direct integration into the carrying harness, it gives this minimalist vest a seamless feeling that you'll swear is an extension of your own body. Bryce Thatcher founded Ultimate Direction and he began hand-sewing hydration packs in 1986. Since that time, Ultimate Direction's lineup has expanded dramatically and now includes signature pieces born of collaborations with professional athletes. Compared to other minimalist hydration systems like the SJ Ultra Vest or the PB Adventure Vest, the AK Race Vest is the lightest and most streamlined model. With his initials in the name, professional runner Anton Krupicka wouldn't have it any other way.