Run hydration consists of hand held bottles with straps, belts with hydration bottles or vests with hydration bladders. Many run hydration options also include a pouch for a few essentials like money, gels and a key. When purchasing a hydration option you should consider how much water you think you will need to bring. Shorter runs that require less water are better suited to one or two bottles, while long distance training will require a four bottle belt or a vest. Other things to consider are a cell phone pocket, reflectivity for low light visibility and insulation to keep your fluids cool.