A few hours before sunrise on January 23, Sunny Stroeer left the Plaza-de-Mulas base camp on Aconcagua under a clear sky, hiking fast along the Normal Route toward the summit 8,501 feet above her. She topped out eight hours and 47 minutes later, breaking the base camp-to-summit female speed record on South America’s highest mountain by 29 minutes, in spite of having a respiratory infection.

The second tallest of the Seven Summits, 22,841-feet Aconcagua sits deep in the Andes on the western edge of Argentina, near the Chilean border. The Normal Route snakes up the mountain’s Northwest Face through three camps and is a famous test-piece for serious mountaineers transitioning to high-altitude peaks. In 2015, then-unknown Karl Egloff broke Killian Jornet’s roundtrip base camp-to-summit time by about an hour. Wanting to keep her legs fresh for a longer speed attempt later in the week, Stroeer decided to walk down from the summit, rather than challenge local guide Chabela Farias’ roundtrip record of 12 hours and 40 minutes.

Before quitting her job and embracing van life in late 2015, Stroeer was a weekend warrior. Despite little training, she finished several 100-mile and 100K trail races with solid times. In 2014, she climbed Aconcagua solo and unsupported. For this trip, she returned to the mountain leading an all-female expedition of four women that included Libby Sauter, a famed Yosemite climber.

If you haven’t heard of Stroeer, now’s a good time to get to know her: the Adidas athlete is just getting started.