Since 1978 men and women have been integrated in companies, usually about 200 to 250 soldiers. Platoons, about 50 soldiers each, have remained segregated. The coed companies have caused problems, the Army said, because men generally outperform women in physical tasks such as long-distance running, road marching and obstacle and confidence courses.

"We feel that if we have women in a male unit it will result in the men not being challenged sufficiently, that they may never reach their full potential," said Capt. Douglas Haywood, a spokesman for the Army's Training and Doctrine Command.

Commanders, he said, "want an entire unit to finish very close together, finish as a unit. You might have the men finishing far ahead of the women, which does not enhance esprit de corps in that unit."

Both men and women were "meeting the standards," Haywood said, "but our goal is to let people do better than the minimum."

After basic training the Army will be as fully integrated by sex as it can be under the law prohibiting women from serving in combat. Female drill sergeants also will continue to be allowed to supervise all-male companies. "If they've gotten through drill-sergeant training," Haywood said, "we feel they can keep up with the men."