Hydration pack
Encyclopedia
Hydration system
In recreation and other sustained outdoor activities, a hydration system is an apparatus intended to help its user in drinking enough liquid to support the physical effort involved in the activity. Such systems for consumers were first sold to cyclists, but by the 1990s also had found a...
built as a backpack
Backpack
A backpack is, in its simplest form, a cloth sack carried on one's back and secured with two straps that go over the shoulders, but there can be exceptions...
or waist pack containing a reservoir or "bladder" commonly made of rubber
Rubber
Natural rubber, also called India rubber or caoutchouc, is an elastomer that was originally derived from latex, a milky colloid produced by some plants. The plants would be ‘tapped’, that is, an incision made into the bark of the tree and the sticky, milk colored latex sap collected and refined...
or flexible plastic
Plastic
A plastic material is any of a wide range of synthetic or semi-synthetic organic solids used in the manufacture of industrial products. Plastics are typically polymers of high molecular mass, and may contain other substances to improve performance and/or reduce production costs...
. The reservoir contains a capped mouth for filling with liquid and a hose that allows the wearer to drink hands-free. Most hoses end with a "bite valve" that opens when the user bites down on it; the valve may be protected by a dust cover. Some hydration packs are insulated to keep water from freezing or becoming warm. Reservoir sizes commonly range from 1.5 to 3.0 litres.
Hydration packs are commonly used for outdoor recreational activities, such as hiking
Hiking
Hiking is an outdoor activity which consists of walking in natural environments, often in mountainous or other scenic terrain. People often hike on hiking trails. It is such a popular activity that there are numerous hiking organizations worldwide. The health benefits of different types of hiking...
, bicycling, and kayaking
Kayaking
Kayaking is the use of a kayak for moving across water. Kayaking and canoeing are also known as paddling. Kayaking is distinguished from canoeing by the sitting position of the paddler and the number of blades on the paddle...
, as well as for military maneuvers.