Survival skills
A human being can survive an average of three to five days without the intake of water. The issues presented by the need for water dictate that unnecessary water loss by perspiration be avoided in survival situations. The need for water increases with exercise.
Inedia
Some breatharians have submitted themselves to medical testing, including a hospital's observation of Indian mystic Prahlad Jani appearing to survive without food or water for 15 days, and an Israeli breatharian appearing to survive for eight days on a television documentary. In a handful of documented cases, individuals attempting breatharian fasting have died. Among the claims in support of Inedia investigated by the Indian Rationalist Association, all were found to be fraudulent. In other cases, people have attempted to survive on sunlight alone, only to abandon the effort after losing a large percentage of their body weight.