Aroa Sío

About

Aroa Sío (born c. 1979) is a Spanish professional ultra trail runner from Galicia whose career is one of the sport's most striking reinvention stories. A former competitive athlete who became Galician champion in the 3,000 metres at age 17, she walked away from the sport entirely and did not race again for nearly 28 years. On September 20, 2015, at age 36, she entered the Trail Montes de Vigo 18K as her comeback race — her first trail race ever — and won it. She quit her job as a special-education teacher, signed with Craft Sportswear, and built systematically toward the international elite level. She placed fourth at the 2021 Skyrunning World Championships representing Spain's national team, won the MIUT 85k in Madeira and set a course record, and earned a Western States 100 Golden Ticket with a third-place finish at the 2022 Canyons by UTMB 100k. In 2026, she won the Canyons Endurance Runs 100-Mile outright — finishing second overall in 19:24 — and placed second at the Arc of Attrition 50 in 9:31:30, confirming her standing as one of the strongest 100-mile racers of her era.

Notable Wins

• — Canyons 100 Mile 2026 (19:24
• — 2nd overall)
• — MIUT 85k (CR)
• — 3rd Canyons 100k by UTMB 2022 (Western States Golden Ticket)
• — 4th Skyrunning World Champs 2021
• — 2nd Arc of Attrition 50 2026

Race History