The mysterious shoes helping the ultra trail queen run a sub-2:39 marathon

American ultra trail legend Courtney Dauwalter achieved a personal best (PB), improving her time by 11 minutes, at the California International Marathon thanks to Salomon's aerodynamic prototype shoes.

Making a rare appearance on asphalt last weekend at the California International Marathon (CIM) 2025 in Sacramento, US, Courtney Dauwalter, widely regarded as the queen of ultra trail running, surprised the running community by completing the marathon distance in 2 hours 38 minutes 55 seconds. This performance secured her a spot in the top 75 at the USATF Marathon Championships and improved her personal best by 11 minutes.

Courtney Dauwalter competing at the California International Marathon 2025 on 7/12. Photo: Instagram / Courtney Dauwalter.

According to Canadian Running Magazine, Dauwalter's secret was a completely new Salomon prototype shoe. This model is believed to be the next iteration of the Phantasm S/Lab series, featuring a carbon plate and a redesigned upper focused on maximizing aerodynamic efficiency.

The shoes first garnered attention a week ago on the Instagram account @the_secret_shoe. A user who tested the prototype at The Running Event in San Antonio described the upper as being made from micro-knit fiber, designed to cover the laces. This design aims to reduce wind resistance and optimize airflow, a feature rarely seen in road running shoes.

Many observers questioned whether aerodynamic factors truly make a difference when an athlete moves at speeds under 20 km/h. This skepticism was particularly directed at Dauwalter, who often competes with a relaxed style, including her distinctive baggy shorts – attire not typically optimized for wind resistance.

Beyond the upper, this prototype is also rumored to incorporate a new, high-rebound foam midsole and an improved energyblade carbon plate. While Salomon has not yet released specific details, these modifications appear to have provided significant assistance, as Dauwalter surpassed her previous personal best of 2 hours 49 minutes 51 seconds in just two months.

The brand new Salomon prototype shoe used by Courtney Dauwalter. Photo: Instagram / the_secret_shoe.

Following the race, Dauwalter shared on Instagram, "I knew I would have to try this distance again. It feels completely different from what I've been doing for years, and I'm excited to explore more."

Salomon has not yet disclosed the commercial release date for this shoe model, but experts anticipate the product may soon be seen on many of the brand's other athletes.

Born in 1985, Dauwalter is widely regarded as one of the world's most outstanding female trail runners. Her status was solidified after she became the first person to win the Western States 100, Hardrock 100, and UTMB consecutively in the same year, 2023.

Dauwalter has been repeatedly honored as "Ultra Runner of the Year" by Ultrarunning Magazine (2018, 2019, 2021, 2022, 2023) and received the George Mallory Award in 2020 for her contributions to expanding the limits of human achievement.

Hong Duy (Canadian Running Magazine).

By VnExpress: https://vnexpress.net/doi-giay-bi-an-giup-nu-hoang-ultra-trail-chay-marathon-sub2-39-4992339.html