I’ve always struggled with efficiency and comfort on longer runs in the mountains, which naturally led to diminished motivation—enter the Nathan VaporKrar 2.0 12-Liter race vest. Lightweight, with an apparel-like fit and internal compression system designed to tighten loads to the body, the VaporKrar provides the all-day comfort I need. The insulated 1.6-liter reservoir keeps water cooler longer and reduces sloshing. Plenty of easy-access stash pockets hold essentials, extra hydration, and even large smartphones. No longer do I struggle with either efficiency or comfort. $200.