Ultimate Direction Signature Series AK Race 40oz., $89.95, and SJ Ultra Vest 40oz., $124.95.
Features: Designed by veteran distance runners Anton Krupicka and Scott Jurek, these vests are lightweight with plenty of thought placed upon construction. Both carry water bottles in front pockets, which our testers enjoyed as a different option than traditional bladders. They’re best as race vests where you can refill your water bottles at aid stations or have some kind of filter (see below) with you for training runs. Not having to carry bottles for those who don’t like bladders, this makes for a great option. The AK is the one to choose for anything up to 50k.
Cons: What you gain in ounces you lose in comfort. There’s no room for padding, so be conscious of where you face zippers, buttons, and fuel bars to avoid chafing and sore spots. Different sizes but limited ability to adjust beyond.