TOKYO — There was a time when slimness was the absolute prerequisite for urban Japanese women, when designers like Shinichiro Arakawa and Yohji Yamamoto professed a flat refusal to make clothes for women who weren't fragile and thin, whose chests and hips were barely discernable through the fabric.

That aesthetic went out when the health and exercise boom came in about seven years ago - the new Japanese woman, according to the fashion critic Ikuko Hirayama, is: "strong, robust, bursting with energy. She takes care of her body but is not obsessed with being thin. She's proud of her biceps and also proud of her sexuality." Accordingly, the most popular relaxation sport for single working women nowadays is "boxercising," or the combination of boxing moves plus aerobics, which is said to increase adrenaline flow by 80 percent and is an ideal way to blow off aggression and stress.

In stark contrast, it's the men who want to be slender, vulnerable and protected. Young males between the ages of 18 and 30 make up the slimmest segment of the population and the ideal fashion weight as decreed by the apparel industry is 57 kilograms, or about 125 pounds, for a height of 175 centimeters, or 5 feet 8 inches. Many men try to adhere to that figure and some claim they want to be even skinnier.

Twenty-five-year-old Junichi Shirakawa, who works at the denim boutique 45 RPM, said that his goal is to get his weight down from 57 to 55 kilograms, although his height is 182 centimeters. "Being really skinny is essential, not just for fashion and work purposes but also because girls seem to go for thin guys," he said.