NATICK, Mass. With enough strength training, women can load trucks, fix heavy equipment and march under the weight of a loaded backpack as well as many men, according to a study by Army researchers.

Seventy-eight percent of the women tested could qualify for Army jobs considered "very heavy," involving the occasional lifting of 100-pound loads, said Everett Harman, the Army scientist who headed the study.

The results prove that "women are capable of being trained to perform most very heavy military tasks," Harman said.

Before the training study began at the Army's Natick Labs, only 24 percent of the women tested could lift 100 pounds.

The volunteers all but one of them civilians were lawyers, bartenders, mothers and students. Many had never exercised before, and several had recently had children and wanted to get back in shape; others were recreational joggers. Each earned $500 for participating.

Critics charged last year that the study, conducted by the Army Research Institute of Environmental Medicine, was a prelude to plans to allow women to engage in hand-to-hand combat. Because of that, the $140,000 study was placed on hold for about five weeks until the controversy subsided.

Women are now excluded from ground combat in the Army and often are rejected for other jobs because they can't perform the lifting tasks, Harman said.

Harman believes it's worth the investment to strengthen military women.

"Some people say, Why should you spend money training women when you can get men off the street?' '' he said.

Harman argues that Army women tend to have more education than Army men, and that it's less expensive and time-consuming to increase a woman's strength than it is to teach an illiterate male to read.

"When people think of this study, they probably think we're bodybuilding, steroid-taking, weight-lifting women," said Jean Haertl, 30, who said she lost 35 pounds over the six months of training. "We range from being very thin and lean to not so thin and lean. We represent the average shape of women."

For 24 weeks beginning in May, 41 women spent 90 minutes a day, five days a week, performing strength tests designed to simulate specific military tasks. Four trainers, all nationally certified, oversaw their conditioning.

The women lifted 40-pound boxes to heights of 52 inches the average height of an Army flatbed truck jogged through a 2-mile wooded course wearing a 75-pound backpack, and performed dozens of squats holding a 100-pound barbell on their shoulders.

The women also were tested on the number of times they could lift a weight in a set period.

For the tests most relevant to military tasks backpacking and repetitive lifting of heavy boxes the women improved 33 percent overall.

Harman measured the women's success against previous Army studies of men on active duty.

In earlier tests, an average Army man could lift a box of 128.5 pounds to a height of 52 inches. Before the study, the women volunteers could lift 70 percent of that. After, they averaged 91 percent of what the men lifted.

On average, Harman said, women tend to have about 70 percent of the lower body strength of men, and 55 percent to 60 percent of men's upper body strength.

Lori Gilstrap, a strength and conditioning coordinator with the U.S. Olympic Committee in San Diego, said she wasn't surprised the women improved, especially because they had never been professionally trained.

But, she said, women can't be expected to match men's strength because they have much lower levels of testosterone. "For women to lift the exact amount that a male could lift, say in a bench press, is going to be very, very difficult," she said.

Lisa Palmer, 28, of Northboro, could barely run a mile when she first joined the study. Now, she said, she runs four with little effort.

"I think that if a woman wants to do the best they can do, they can do almost anything," she said.