Whether you're doing an ultra or just running for fun, it's important to be prepared. Water, food, first aid kit, extra layers - these are all things you need to consider when heading out. This is why it's worth putting serious thought into what pack you carry. It's vital to be able to take your essentials on the run, but to do it comfortably is equally important. Who wants to run with a bouncing lump on their back?

Fortunately, Jack Hart has tested the best middleweight hydration packs out there to give you a head start.