In various martial arts 
In kyūdō, zanshin means the body posture after the loosing of an arrow; the posture is intended to reflect the higher meaning of zanshin, which is a mental aspect maintained before, during, and after an action.
In the context of kendō, zanshin is the continued state of spirit, mental alertness and physical readiness to meet the situation (such as an opposing attack) that must be maintained when one returns to kamae after attacking. It is one of the essential elements that define a good attack.
During the practice of aikidō, the usual method of practicing zanshin is to focus on the just-thrown uke, or opponent, while holding kamae and maintaining awareness in case there are additional attacks or attackers. In Iwama Style training, zanshin is practiced as general awareness of one's surroundings, of which uke is just a small part.
Within the context of ninjutsu, especially inside Bujinkan, zanshin is a collective simulated combat in total or partial darkness, that allows one to become more acquainted to fighting without the aid of light.
See also 
- "One arrow, one life: Zen, archery, enlightenment" by Kenneth Kushner; Tuttle Publishing, 2000, page 73
- "The complete idiot's guide to karate" by Randall G. Hassell, Edmond Otis; Penguin, 2000, p. 26-27
- "The Essence of Okinawan Karate-Do" by Shōshin Nagamine; Tuttle Publishing, 1998, page 100
- "Complete Kendo" by John J. Donohue; Tuttle Publishing, 1999, page 89
- "Kyudo: the essence and practice of Japanese archery" by Hideharu Onuma, Dan DeProspero, Jackie DeProspero; Kodansha International, 1993, p. 84-85
- "Karate" by Kevin Healy; Connections Book Publishing, 2002, page 21
- "Advanced Aikido" by Phong Thong Dang, Lynn Seiser; Tuttle Publishing, 2006, page 64
- "Dynamic Aikido" by Gōzō Shioda; Kodansha International, 1977, page 107