Hiking is an outdoor activity which consists of walking in natural environments, often on hiking trails. Hiking may be broadly grouped into two categories.
Wilderness backpacking involves a multi-day hiking expedition where participants carry the required supplies for 2 or more days of survival in the wilderness, and camp en route.
Day hiking involves distances of less than a mile up to longer distances that can be covered in a single day.
The following section in the WikiVoyage article about the Appalachian Trail also applies to all other long-distance paths:
The most common cause of failure to complete a trail is lack of preparedness. It is important to begin regular walks in the months and weeks leading up to the thru-hike, beginning with low-impact day-hikes in easy terrain while carrying a minimum of weight. When these day-hikes become nearly effortless, increase the distance and include several multi-day hikes that require a full backpack with food, water and gear. In addition, hilly terrain should be incorporated as soon as possible in order to build up strength in the muscles required for climbs and descents. Performing regular hikes that continually push the body's current limits will not only toughen the body but will also go a long way toward mentally preparing oneself for the constant strain on body and mind.
Preparing financially and logistically are also essential to a successful thru-hike. The cost of a hike will range from several hundred dollars a month on the low end to upwards of a thousand dollars a month for the high end. Each person has a different minimum level of comfort and nourishment; it is vital to discover what one's own level is as early as possible and to make supply arrangements accordingly. Study the route and identify towns that will serve as likely resupply centers and map out distances between post offices. An experienced thru-hiker resupplies his or her dry goods every 10-14 days, either through the post offices or through local purchases.
Equipment should be purchased well in advance of the start date and should be used as many times as possible to both allow the hiker to become familiar with the gear (backpacks adjusted properly, boots broken in, etc.) and to identify any broken, impractical or unsatisfactory items. Prospective thru-hikers should get in contact with local hiking clubs and solicit advice on what pieces of equipment are completely unnecessary, which are luxury items and which are essential. Different hikers have different philosophies on how much gear should be taken, from those in the "lean and fast" school of thought which advocates a minimum of everything - no stove, no tent, hiking sandals instead of boots and little else - to the "slow and comfortable" school which sacrifices speed and low weight for comfort. One should get as many opinions as possible and attempt hikes with various levels of gear until an acceptable amount of weight and speed has been achieved.