20th or 21st century. There are many aspects to the kaihōgyō, but the main portion of walking meditation can be broken down into the following sections: Practices There are two kaihōgyō practices; 100 days (hyaku-nichi kaihōgyō) and 1,000 days (sennichi kaihōgyō). The ultimate achievement is the completion of the 1,000-day challenge, which would rank among the most demanding physical and mental challenges in the world. Only 46 men have completed the 1,000-day challenge since 1885. Of these, three people have completed the circuit twice, most recently , who first went from 1973 to 1980 and then, after a half year pause, went again, finishing his second round in 1987 at age 60. The kaihōgyō takes seven years to complete, as the monks must undergo other Buddhist training in meditation and calligraphy, and perform general duties within the temple. They are required to spend 12 years total on Mount Hiei and includes vows of lifelong celibacy and sobriety in the spirit of renunciation. The training is divided into 100-day sections as follows: The walking meditation is punctuated in the middle of the term by the Katsuragawa retreat which takes 4 days. Although not required, all modern initiates have been known to add the missing days due to this retreat onto the end of their course, thereby completing the full 1000-day term. Author John Stevens, in his book, The Marathon Monks of Mount Hiei, describes the long distance walking style which dates back over a thousand years: "Eyes focused about 100 feet ahead while moving in a steady rhythm, keeping the head level, the shoulders relaxed, the back straight, and the nose aligned with the navel." Dōiri or "Entering the Temple" During the fifth year of the challenge, the walking practice is punctuated by what many consider the most daunting phase of the process. The ascetic monk must go for nine days without food, water, or rest of any kind. He sits in the Temple and recites the Fudō Myōō mantra constantly. Two monks accompany him, one on either side, to ensure he does not fall asleep. At 2 am every night he must get up to fetch water for offering from a special well, around 200m away, as an offering for Fudō Myōō. ClothingKaihōgyō practitioners are thought to represent a living Fudō Myōō, and each item of clothing symbolises this in some way. Practitioners wear a distinctive hat made from woven