Lazarus Lake, the race director of the Barkley Marathons, made a controversial claim in 2015 stating that women were not tough enough to complete the grueling ultramarathon. His statement was challenged nearly a decade later when British ultra-runner Jasmin Paris completed the 100-mile race with just one minute and 39 seconds to spare of the 60-hour time limit, setting a historic precedent. Since then, female runners have increasingly competed with and even surpassed male runners in ultramarathons, breaking records and winning races outright. Last summer, a female one-two finish was recorded in the Montane Summer Spine Race, and Rachel Entrekin became the first woman to win the Cocodona 250 in Arizona. Recently, Sophie Woods shattered the Via Alpina record by six days, further highlighting the growing presence of women in the sport. The question of whether female runners have physiological or psychological advantages in endurance events has sparked interest among sports scientists and athletes alike. In races up to the marathon distance, men typically outperform women by 10-12%. However, in 100-mile races, this gap narrows significantly to just 0.25%, and for races longer than 195 miles, women may even have the potential to be faster. Possible reasons for this include higher fat stores, more oxygen-efficient muscle fibers, and greater fatigue resistance. However, experts like Professor Andy Jones and Dr. Richard Burden emphasize that more research is needed to confirm these potential advantages. Ultra-endurance events are not only physically demanding but also mentally taxing, often involving multi-day challenges, sleep deprivation, and extreme conditions. Mental resilience is a key factor, and many female runners credit their success to strong mental focus and adaptability. Sophie Woods, who completed the Via Alpina, highlights the importance of mental strength, while Yngvild Kaspersen, a two-time winner of the Ultra-Trail Mont Blanc CCC race, points to the supportive community among female runners. Sports dietitian Renee McGregor notes that women may have developed greater endurance through managing fluctuating hormones from puberty and employing disciplined pacing strategies. Despite these potential advantages, women make up only about 20% of ultramarathon participants. Efforts to increase female participation include initiatives aimed at achieving gender parity in events. Rachel Entrekin’s victory at Cocodona 250 has inspired many other female runners, and social media influencers like Emily Fairs are encouraging more women to take part in the sport. Fairs believes that recent success stories indicate that female dominance in ultra-running is just beginning, and the future of the sport remains uncertain but full of potential.