An Air Force volunteer performs a rescue simulation as part of a study of combat's physical demands.

An Air Force volunteer performs a rescue simulation as part of a study of combat's physical demands.


Feature: As U.S. moves to allow women in combat, researchers help set the bar

LACKLAND AIR FORCE BASE, SAN ANTONIO, TEXAS—On a sunny June afternoon, a U.S. Air Force airman is staring up at a 2.5-meter wall. The young woman has just lugged more than half her weight in gear down 5 kilometers of a dirt jogging path and dragged a 98-kilogram dummy across a long stretch of grass. She's already failed at one attempt to clear the wall. Now the clock is ticking: She has 2 minutes to make it or move on to the next task.

“Why am I so dizzy?” asks the airman, who cannot be identified by Science under the study's privacy rules. She's determined to get over. This obstacle course, designed to mimic the physical demands of military combat, is her last challenge in a 2-week Air Force study. So far, she hasn't had to leave anything unfinished.

She has volunteered for the grueling exercise along with nearly 200 other airmen (the term used for both men and women) in order to help answer a thorny question: How should the U.S. military decide who is physically qualified to be a combat soldier? That question is getting urgent attention since the Department of Defense moved in 2013 to integrate women into ground combat roles—the last military occupations to remain male-only.

By January 2016, each branch of the military—the Army, Air Force, Navy, and Marines—must open up its combat specialties to females or ask the Secretary of Defense to keep the gender restriction on certain jobs. The deadline has prompted a slew of new research projects, including studies of physical standards, gender differences in injury rates, and service members' attitudes towards integration. But the surge of new science has also prompted suspicions that the services will arbitrarily lower standards in order to meet political demands for equality.

“For a lot of people, this isn't a scientific issue. It's a very emotional issue,” says Jennifer Hunt, an Army Reserve staff sergeant and Iraq veteran in Gaithersburg, Maryland, who is one plaintiff in an ongoing lawsuit against the Pentagon aimed at lifting the ban on women in combat. “There's a big sociological aspect to it—of how we conceptualize a woman's role.” The lawsuit is on hold as the military decides whether to keep any positions closed.

The legal and political backdrop can make for a highly charged research environment, in which a wall standing on a Texas air base is more than just a wall. The airman, who in her spare time is a competitive weight-lifter, has her eye on one of the soon-to-open combat specialties, such as pararescue. “I work behind a computer and there's no windows, all damn day,” she explains at one point. “I absolutely hate it.” That may be why, on her second try, she approaches the barrier with a certain ferocity.

To simulate combat, subjects in an Air Force study crawled across a simulated battlefield while wearing 43 kilograms of gear (left) and carried a nearly 50 kilogram barbell—about one half the weight of a casualty on a stretcher.

To simulate combat, subjects in an Air Force study crawled across a simulated battlefield while wearing 43 kilograms of gear (left) and carried a nearly 50 kilogram barbell—about one half the weight of a casualty on a stretcher.


THE QUESTION OF whether to open ground combat positions to women has sparked decades of controversy, but attitudes—and government policies—are evolving. In the past 3 decades, Canada, Australia, and many nations in Western Europe have moved to do away with combat restrictions, and the United Kingdom is currently reconsidering its policy. In part, the changes reflect the fact that women have already served and died alongside men in combat, despite their formal exclusion. In conflicts without clear front lines—in Afghanistan and Iraq, for example—female medics, pilots, engineers, and intelligence analysts have all been exposed to enemy fire.

Women in the U.S. military have been selected for increasingly risky jobs. In 2010, for instance, the military created all-female “cultural support teams” that served as liaisons between U.S. forces and Afghani women, collecting information and sometimes joining Army Rangers on dangerous raids. Former Secretary of Defense Leon Panetta emphasized women's combat experience when he announced, in January 2013, that the military would lift a categorical ban on women in units whose mission is to “engage in direct combat on the ground.” At the time, the policy applied to more than 250,000 positions. “The fact is that [women] have become an integral part of our ability to perform our mission,” Panetta said.

Still, questions persist about the physical abilities of female service members. On average, women have smaller hearts, slighter skeletons, less muscle mass, and more fat than males, noted a report on woman in combat published last December by the U.K. Ministry of Defence. Analysts worry those attributes could make it difficult for women to perform certain critical combat tasks, such as loading heavy artillery, conducting rescues, or bearing heavy combat loads, which can exceed 45 kilograms of weapons and gear. The U.K. report concluded that “the relative strength of females, compared to the combat load carried, is likely to result in a distinct cohort with lower survivability in combat.”

THE YOUNG AIRMAN eyeing the wall is intent on proving to military leaders that such statistics about “average” females aren't meaningful—that some women can meet the physical demands of combat. In the Air Force, those demands might include scouting for days behind enemy lines to coordinate an air attack, or parachuting into a battle zone to evacuate the wounded. “We are going up against a pretty big cultural block,” the airman says. “Women in these career fields are generally seen as a hindrance, a burden: ‘Oh, she's not going to be able to keep up. I'm going to have to drag her equipment.’”

So for the last 2 weeks, she has been sweating in the Texas sun and feeding data to Neal Baumgartner, a long-time exercise physiologist for the Air Force who designed and is running the study. Baumgartner, 55, is a retired major who has been “bleeding blue for the Air Force since I was 17.” And he has been waiting for more than a decade to do this research.

Baumgartner has long argued that the physical standards that combat airmen must meet to advance through training (which can last 6 to 24 months) should be based directly on the demands of real-world fighting—not, as is currently the case, on the physical fitness traits of previous candidates who have successfully completed the training. But in 1998, when Baumgartner first proposed running a study to reexamine the standards, the Air Force said funding wasn't available. He kept chipping away at the project, and in 2011 worked with the RAND Corporation to design the study.

When Baumgartner first conceived the research, he didn't anticipate that some of his subjects would be women. But the funding only began to flow after the Pentagon lifted its ground combat exclusion. Military leaders developed a policy, known as the Women in Service Review (WISR), which required the Air Force and other services to demonstrate that the occupational standards for combat jobs were scientifically defensible and gender neutral. Air Force officials asked: “Is anybody doing this work?” Baumgartner recalls. “Boom. We already had it in place.” His study finally had official backing—and a hard deadline. By this week, he will submit his recommended standards to the secretary of the Air Force.

Baumgartner moved quickly to recruit subjects—63 female airmen and 109 male airmen, about half of them current combat soldiers. During their first week in the study, subjects took 39 physical fitness tests: They squat-lifted dumbbells of increasing weights to find their limits, did crunches to the beep of a metronome until exhaustion, and tested their upper body strength on a pull-up bar.

Week 2 brought 15 combat and rescue simulations, all based on “mission profiles” that current battlefield airmen carry out to prepare for deployment. The test subjects evacuated a dummy named Rescue Gumby from a vehicle and towed another, Rescue Randy, back and forth across a swimming pool. They scaled a 6-meter rope ladder with 30 kilograms of gear. The weight makes most climbers tilt backward towards the horizontal, Baumgartner notes. “You end up like a turtle.”

After collecting data, he began comparing the results of the 39 fitness tests and 15 simulations. He's looking for correlations. For example, does the ability to do crunches predict how fast an airman can climb a rope ladder, or do push-ups correlate better? He will also define what constitutes “success” on a simulation by surveying experienced combat airmen who have performed the tasks and consulting a panel of military experts. For instance, how long should it take a rescuer to drag an injured comrade from a damaged vehicle, or hoist a rucksack over the slippery side of an inflatable Zodiac boat? Finally, he is developing practical standards that the Air Force can use to judge whether an airman is physically fit for combat: a minimum number of crunches, for example, or swimming a certain distance within a time limit.

Setting those magic numbers is a balancing act. Ideally, any cutoff should minimize the number of people who might meet the fitness standard but then fail the simulations. But it will also need to avoid axing less fit recruits who might succeed on actual combat tasks.

Although Baumgartner is often careful to explain the study's nuances to his subjects, misconceptions abound. The young female airman shooting for a perfect completion record, for instance, can't shake the notion that her data will count for more if her performance is exceptional. “We are here to set the standards as high as humanly possible so that when women behind us actually start moving into the community, they are absolutely equals [to men],” she says. “I have this phrase in the back of my head: ‘I will not be the reason they lower that standard.’”

In reality, the study is gender-neutral; Baumgartner is trying to develop measures that can predict whether any recruit, male or female, can handle the physical demands of certain combat tasks. A strong performance won't necessarily bump the standard higher. It just adds another point to Baumgartner's scatterplot—designed to detect good correlations and compensate for outliers.

Still, some fear that the Air Force will lower the bar so that more women will clear it. One experienced battlefield airman in the study admits that he came in skeptical. “If you're going to open up career fields to females and make it gender-neutral, just have them run in, and shoot for the [existing] standard,” he says. “We have guys that have been doing it for years, and the standard has been the standard.”

Ultimately, any final decisions about which positions to integrate and where to set the standards will be made behind closed doors at the highest levels of the Pentagon and White House. For now, however, the Air Force doesn't anticipate keeping any of its combat positions closed to women.

OTHER BRANCHES of the U.S. military are also scrambling for new data. The Army, for example, plans to create a screening test for new recruits. The goal is to disqualify some recruits—male or female—from pursuing combat training if the results suggest they are unlikely to complete the training or likely to get injured attempting it. Using actual combat tasks for such screening often isn't practical, notes Jack Myers, a senior planner with the Army's Training and Doctrine Command and a lead on the integration initiative. “Imagine a high school senior showing up at a recruiting station and we're like, ‘Okay, I need you to load this howitzer.’”

In 2013, when the U.S. defense department lifted its categorical ban on women in combat, more than 250,000 direct ground combat positions were male-only.

In 2013, when the U.S. defense department lifted its categorical ban on women in combat, more than 250,000 direct ground combat positions were male-only.


Instead, physiologists at the U.S. Army Institute of Environmental Medicine in Natick, Massachusetts, are designing a predictive model. It reduces previously male-only jobs to their five to seven most physically demanding tasks, which are further simplified into exercises like a long jump or a grip test that could be performed at a recruiting station.

The Marine Corps is trying to evaluate another issue: how females might affect a team's performance in a combat mission. The Corps' 350-person study group, known as the Ground Combat Element Integrated Task Force, includes about 65 women who have already completed the occupational specialty schools that feed into combat jobs. Some are trained as machine gunners, for example, and others learned to operate antitank missiles. This past spring, at a base in Twentynine Palms, California, the volunteers were tested in 12-member teams, some all-male, some including either one woman or two. The teams carried out test missions, sometimes with live ammunition, while GPS sensors and heart monitors tracked each volunteer's accuracy, speed, and exertion.

The data will allow researchers to compare the performance of male-only teams with integrated ones—how accurately the team explodes its target, for example, or how quickly it traverses difficult terrain. Researchers can also compare how much females must exert themselves on a given mission relative to their male teammates, and whether they sustain more injuries.

“That's a really important landmark study,” says Daniel Billing, a human performance scientist with the Australian Defence Force, which in 2011 announced it would open 24 combat roles to women. The government's Defence Science and Technology Organisation in Melbourne has been evaluating its own occupational standards, and is watching the U.S. research with interest. “I'm hoping that with the facts on the table, it will allow people to move from identifying reasons why women should not serve in these roles, to start getting really productive and looking at the strategies that might best accommodate and support females,” Billing says.

Injury experts are already thinking about how to provide such support to women. Musculoskeletal injuries—damage to joints, muscles, tendons, ligaments, and cartilage, often from overuse during training—have long taken a major toll on service members. An estimated 24% of evacuations from recent U.S. operations, for example, were the result of musculoskeletal injuries, not combat injuries. And military women appear to be at greater risk: In the Army, which has the highest rate of training-related injuries, studies have found that about twice as many women as men sustain a musculoskeletal injury during basic training.

Whether the women in the newly opened positions will also face a heightened injury risk is “the big open question,” says Bruce Jones, a physician and epidemiologist who manages the injury prevention program at the U.S. Army Public Health Command in Aberdeen, Maryland. He has been analyzing injury data since the early 1980s, when a commander asked him to figure out whether his trainees would be better off running in running shoes or combat boots. (“We were never allowed to do the study,” Jones says, because “the issue was resolved” when the chief of staff simply decreed that trainees would wear running shoes.)

Jones and his colleagues have found that fitness, not gender, may underlie the injury risks. In a 2000 study of basic training recruits, they showed that differences in aerobic fitness, as measured by run times, accounted for most of the twofold difference in injury rates between men and women. That suggests “men and women of the same fitness level have similar risk,” Jones says, adding that it's not yet clear whether that pattern will hold among combat soldiers.

In a bid to prevent injuries, a new working group within the Army Medical Command is developing recommendations for safer training regimens. There is already some evidence that high-intensity, low-volume training—substituting short sprints for long hikes and jogs, for example—can reduce overuse injuries and improve performance in both men and women. And as women join the combat ranks, the working group hopes to use records of medical visits and time lost to injuries to identify any female-specific risks and suggest prevention measures. But it will be up to unit commanders to decide whether and how to implement any injury-prevention recommendations.

WITH OTHER SUBJECTS threatening to overtake her, the airman takes another shot at the wall. She flings herself up, grips the top, and wriggles like a worm. When she manages to get a foot over the wall, other subjects, who Baumgartner has discouraged from watching or cheering, watch and cheer.

Half an hour later, she hauls a 48-kilogram barbell up an incline that replicates the ramp of a C-17 cargo plane and hoists one end of a weighted stretcher above her shoulders. The task simulates loading a casualty—and it's the last one of the day. “Everything is a pass, right?” she asks. “Somebody look me straight in the eyes and tell me I passed everything.”

She doesn't get a response. But as she gets ready to return to her desk job, the airman says she's proud she was able to “get some data in the system” to support women entering the new positions. She knows that even this study can't accurately gauge how women will perform in combat—in part because those in the study haven't trained for it. But she's confident that she and many of the female volunteers could make the cut. “Give us the proper time and training to build those muscles, and we'll keep up with the boys, no problem,” she predicts. “We absolutely could have smoked this stuff.”

A final decision on whether she will get that chance is expected early next year.