Sarah Kopelovich, 23, practices her open handed punches during a krav maga class in self-defense. (Michael Temchine/For The Washington Post)

The latest activity to fill gyms is more self-defense than workout, more psychological than physical. Developed by the Israeli military in the 1950s and imported here in the 1980s, the self-defense system for men and women of the Israeli Defense Forces is now taking over gyms in Manhattan and across the U.S.

But krav maga isn’t for pansies.

“Women are taught that they have to be gentle and kind,” Matan Gavish, 29, a former Israeli Special Ops soldier who runs the Krav Maga Academy in New York told the Inquisitr, a news Web site. “The hardest thing in krav maga is to transform yourself from an educated, well-mannered person into a super-aggressive, super-destructive being.”

See krav maga in action below:

Centered on hand-to-hand combat, krav maga, which means “close contact,” is said to improve hand-eye coordination, quicken reflexes, and increase confidence through a combination of punches, kicks, blocks and strikes. It relies less on learned sets of stances and more on the student’s natural reactions to a situation.

Gavish sums up the purpose of krav maga this way: “You make yourself crazier than the guy who is trying to hurt you.”