Extreme Sports: What Women Are Capable of in Ultra Running

Completely exhausted, she hangs over the yellow gate, the simple finish of one of the toughest ultramarathons in the world. Her skin is scratched by brambles, her eyes are closed, her mouth is slightly open as she gasps for air. British Jasmin Paris had been on the road for 59 hours, 58 minutes and 21 seconds. She finished the race just 99 seconds before the 60-hour limit – becoming the first woman ever to complete the legendary Barkley Marathon at Frozen Head State Park in Wartburg, Tennessee. The race’s founder, Gary Cantrell, once thought this was impossible.

Since 1989, around 1,000 selected people have taken part in this race, only 20 – including Jasmin Paris – have completed the five laps through the pathless terrain with a compass and map within the time limit. The route covers around 100 miles, or 161 kilometers, and 18,000 meters of elevation gain. “The last few minutes to the finish showed me what I was capable of,” said the 40-year-old Brit in an interview.

What women are capable of in ultrarunning, i.e. in races of 50 kilometers or more, has not only been discussed since this historic success. Back in 2019, Jasmin Paris, mother of two and veterinarian, set the course record at the Montane Spine Race, one of the toughest ultra trail races in Great Britain. It took her 83 hours to cover the 268 miles (431 kilometers) – twelve hours less than the fastest man in front of her.

Other women also do extraordinary things. In October 2020, American Courtney Dauwalter won the Big’s Backyard Ultra in Bell Buckle, Tennessee, setting a course record by running a 6.7-kilometer lap every hour for 68 hours. In 2023, she became the first person to win the three most important 100-mile races in the world: the UTMB in Chamonix and the Western States 100 and Hardrock 100 in the USA.

In 2020, the blog “RunRepeat” published an analysis from which a surprising thesis emerged: the longer the race, the better women perform. More than five million finish times and average paces from almost 15,500 ultra running events were examined. While women are on average 11.1 percent slower than men in marathons, this gap decreases dramatically for longer distances. In 100-mile races the difference is only 0.25 percent; in distances over 195 miles, women were on average 0.6 percent faster.

Despite success: women are underrepresented in ultrarunning

However, Nicholas Tiller, a physiologist at the Lundquist Institute at the UCLA Medical Center in Los Angeles, has doubts about the methodology of this evaluation. “Comparisons based on these numbers are difficult because only about 20 percent of the starting field is female,” he says. Together with other researchers, Tiller published a study in 2022 that also examined physiological factors. The research found that women have certain physiological advantages that make them particularly suitable for longer races – they burn fat more efficiently and their muscles are more resistant to fatigue. Men, on the other hand, benefit from better oxygen absorption over shorter distances. But according to Tiller, psychological factors also play a role: women tend to manage their energy well and modulate their pace efficiently over long distances.

In another study, Tiller and his colleague Camilla R. Illidi examined races in which equal numbers of men and women started. This study found that men most likely have an advantage in 50-mile races because of their larger hearts and lungs. In 100-mile races, the difference in performance was no longer statistically significant at just four percent. Men and women also had similar chances of finishing in the top 20 percent of the field, indicating a closer proximity in performance over longer distances. Tiller emphasizes that women do not generally have an advantage, but that the longer the race and the higher the proportion of women, the more women come closer together.

“But whether women are as fast as men is actually not that important,” says Tiller. Rather, he is interested in why women are still underrepresented in ultrarunning. After all, there is no biological reason why men and women cannot take part in these races in equal numbers.

Tiller sees initiatives like the Baker Trail Ultra Race and the High Lonesome 100 in the US as steps in the right direction. Both events promote an equal gender distribution. Surveys after the races showed that many women felt motivated because the organizers had specifically targeted female athletes in order to recruit them for their races. The somewhat simplistic calculation: When women see other women on the track, they feel encouraged to also try out challenges that are traditionally considered “male”.

At the same time, research reveals that a “gender research gap” also exists in endurance sports – a research gap regarding differences between men and women. It was long assumed that hormonal, cycle-related fluctuations in women could distort research results. These assumptions are now considered refuted.

With the “Further” project, which took place in California this spring, the initiators aimed to further close the research gap. They held a six-day ultra race in California that included ten women of varying abilities. In one lap, the athletes ran the longest distances of their careers, set records and, through close monitoring, provided specific data on women’s physiology in endurance sports.

And how does Jasmin Paris classify her historic performance at the Barkley Marathon? A key advantage, she says, was her socialization in fell running – a discipline that originated in Great Britain in which participants complete orienteering runs through hilly terrain. She also cites aspects that are reminiscent of Tiller’s research work – Paris prepared meticulously for the races, benefited from her ability to multitask and distribute her strength correctly over the long distances. What was crucial, says Jasmin Paris, was her “obsession” with wanting to finish the race successfully. It took three attempts.

Paris says she never felt like she had to overcome any special barriers as a woman in ultrarunning: “I just believe that I have the skills to take on challenges like Barkley.” In the end, ultrarunning is about being with yourself measuring yourself against others and pushing your own boundaries – a motivation that drives men and women alike.